medium

GHSA-p538-c434-8v24

PyPI · GitPython

Summary

GitPython: Arbitrary file truncation via git rev-list --output argument injection in unguarded Commit.count

Severity
medium
CVSS
5.4
CWE
CWE-88
Published
2026-08-03
Updated
2026-08-03

Advisory details

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

  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

References

Related advisories

Is your project exposed to this? Stateward checks every dependency on every pull request and flags it only if your code actually reaches it.

Check my repo

Summarize with AI

ChatGPTClaudePerplexity

Sources: CISA KEV (public domain), OSV.dev & GitHub Advisory Database (CC-BY-4.0), FIRST EPSS, NVD/CWE (public domain). Served live from the Stateward advisory database.