GitPython: Arbitrary file truncation via git rev-list --output argument injection in unguarded Commit.countGHSA-p538-c434-8v24
MEDIUMFix: gitpython-developers/GitPython#2184GHSA-p538-c434-8v24 is a medium-severity (CVSS 5.4) CWE-88 vulnerability in gitpython. A fix is available for gitpython — see the affected versions and patch details below.
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for GHSA-p538-c434-8v24.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
gitpythonReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
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
commit.count(output='/path/to/victim') # victim truncated to 0 bytes (verified)
# control: commit.iter_commits(output=...) raises UnsafeOptionError
Attack Chain
- 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. - 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
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | gitpython | all versions | 3.1.56pip install --upgrade 'gitpython==3.1.56' |
Affected Products
gitpythongitpython_projectDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for gitpython, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update gitpython to 3.1.56 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-p538-c434-8v24 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
Moderate: This GitPython flaw enables arbitrary file truncation to zero bytes when an application passes untrusted input to the `Commit.count()` method. Exploitation requires an attacker to control arguments supplied to this method, which is not a default behavior in typical Red Hat deployments, thus limiting the…
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.Source: Red Hat security advisory for GHSA-p538-c434-8v24 (CC BY 4.0)
Frequently Asked Questions
Is GHSA-p538-c434-8v24 in your dependencies?
Find it across PyPI, including transitive dependencies.