prowler · filelock: ReadWriteLock on Windows acts on SQLite side files another local user places beside its database
Affects prowlerSource GCVE Database
Not known to be exploited · CVSS 3.3 Low : upgrade to 5.45.0_1 when convenient.
Data as of 30 Oct 2026, 05:15 UTC
- Patch
- Available – fixed in 5.45.0_1
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:LExploitation evidence
Disclosed: evidence found.
CVE published 29 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.
What to do
Upgrade prowler to 5.45.0_1.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Homebrewprowlerpkg:brew/prowlerOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
On Windows, `ReadWriteLock` and `AsyncReadWriteLock` (the SQLite-backed reader/writer lock) connect SQLite to the lock database by its path, in every directory. SQLite derives three side files from that path: `<database>-journal`, the rollback journal (pages saved to undo an interrupted write); `<database>-wal`, the write-ahead log (changes kept outside the main file); and `<database>-shm`, the shared-memory index of the WAL. SQLite acts on whichever of these it finds beside the database before the lock runs any statement. Another local account that can create files in the database's directory, but not delete files of other accounts there, places such a side file beside the database and denies everyone `DELETE` on it, which a file's creator may do. `C:\Windows\Temp` (the temporary directory of services, granting `BUILTIN\Users` create but not delete) and `C:\Users\Public` are such directories. With a `-wal` in place, every `read_lock()` and `write_lock()` of the user running the lock (below: the lock user) raises `sqlite3.OperationalError: disk I/O error` at once, whatever `timeout` says, until that account removes its file; the lock user cannot. With a `-journal` beside a lock database that holds a table, SQLite replays the journal and deletes the file the journal names, a file of the lock user, and the acquire reports success. Affected versions are filelock 3.20.4 through 4.2.0 on Windows. The maintainers found this while reviewing the fix for the POSIX form of the defect, GHSA-v4x8-3wr5-3wq8, whose text says "Windows does not take this path" (review round 4, finding F2 of set D). It is not among the findings of the report Anthropic's OSS Scanner sent on 15 October 2026. ## Severity **CVSS 3.1 `CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L` scores 3.3 (Low).** `AV:L` (local): the other account needs a logon on the same host. `AC:L` (low attack complexity): create one file beside the database and set its ACL (access control list); no race, and the other account can place the file days earlier. `PR:L` (low privileges): an ordinary account that can create files in the directory is enough. `UI:N` (no user interaction). `S:U` (scope unchanged). `C:N` (no confidentiality impact): the other account learns nothing. `I:N` (no integrity impact in the scored variant): see the scoring note. `A:L` (partial availability impact): every acquire fails with an exception that `Timeout` handlers do not catch, until the other account removes its file; no crash, and the lock's own data is not changed. Scoring note. The deletion variant reads `CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:L` (3.6): `I:L` because the lock user's process deletes one file the journal names, `AC:H` because it needs a lock database that holds a table, which filelock does not create, and a journal the lock user can open for writing. The lower-reading rule of this advisory set scores the variant that reaches every `ReadWriteLock` on Windows in such a directory, 3.3, and describes the deletion variant under Mechanism. Classification from the review: **security** (another account), availability for the scored variant. ## Scope and preconditions - Platform and classes: Windows only. `ReadWriteLock` and `AsyncReadWriteLock`, both of which connect through `_connect`. On Linux and macOS the lock takes other routes, covered by GHSA-v4x8-3wr5-3wq8. - Directory: one where another account can create files but cannot delete the lock user's. `C:\Windows\Temp` carries `BUILTIN\Users:(CI)(S,WD,AD,X)` (create file and create subdirectory, no delete child); `C:\Users\Public` and any directory with such an entry qualify. A directory only the lock user can write, such as `%LOCALAPPDATA%` or the per-user temporary directory, is not affected. - The other account creates `<database>-wal`, grants everyone modify and denies everyone `DELETE` on it. A file's creator may set both. The lock user can open and read the file but not delete it. - Deletion variant: the lock database holds at least one table (filelock creates an empty database, and the review's reproducer has the lock account create the table), and the other account's `<database>-journal` grants the lock account modify rights. The journal's tail names a file the lock user can delete. - What the lock user sees: `write_lock(timeout=1)` raised `sqlite3.OperationalError: disk I/O error` with the undeletable `-wal` in place; with the writable journal the acquire succeeded and the named file was gone; with an undeletable journal every acquire raised `sqlite3.OperationalError: unable to open database file`. - The documentation at the scanned commit states "the lock directory must not be writable by untrusted users" for `WindowsFileLock`, in its symlink paragraph; the `ReadWriteLock` documentation names no directory requirement on Windows. ## Affected code Scanned commit `b831496b0273`: the [Windows branch of `_connect`](https://github.com/tox-dev/filelock/blob/b831496b0273ecd11bf02b8d080ca8b673a538c1/src/filelock/_rea
References
- github.com/tox-dev/filelock/security/advisories/GHSA-9vhv-jxww-xfm5 (opens in a new tab)
- github.com/tox-dev/filelock/pull/834 (opens in a new tab)
- github.com/tox-dev/filelock/commit/5e3f2ec0c5fb17cb2635b60b2b68bc63ab81ca2d (opens in a new tab)
- github.com/tox-dev/filelock (opens in a new tab)
- github.com/tox-dev/filelock/releases/tag/4.2.1 (opens in a new tab)