Описание
GitPython: TagReference.create positional reference bypasses kwargs-only --file guard, enabling arbitrary file read (incomplete fix of 3af0c251)
Summary
TagReference.create() forwards a caller-influenced positional reference value into git tag without it ever being inspected by the unsafe-option guard, allowing an arbitrary file read (the file's contents are returned in-band as the annotated tag message). This is an incomplete-fix bypass of commit 3af0c251 (the fix for GHSA-3f7w-8rr8-f37f's tag instance).
Root Cause
The fix 3af0c251 added unsafe_git_tag_options = ["--file","-F"] and a guard call, but the guard is Git.check_unsafe_options(options=Git._option_candidates([], kwargs), unsafe_options=...) at git/refs/tag.py:139 — it passes an EMPTY args list and inspects kwargs only. The dangerous values path and reference are POSITIONALS (args = (path, reference), tag.py:156), placed before any --. A user-influenced reference="--file=<path>" therefore reaches git tag as the exact --file option the fix intended to block, creating an annotated tag whose message is the file's contents.
Impact
Arbitrary local file read at the privileges of the host process; contents returned in-band via tagref.tag.message. Requires the embedding application to forward a caller-influenced reference value into TagReference.create() (pure VALUE control — the CVE-2026-42215 threat model). Default allow_unsafe_options=False.
Proof of Concept
Attack Chain
- Entry: app calls
TagReference.create(repo, name, reference=<user>)withreference="--file=/home/app/.ssh/id_rsa". - Check:
Git.check_unsafe_options(_option_candidates([], kwargs), ["--file","-F"])@ tag.py:137-141. Guard: denylist includes--file/-F. Bypass proof:_option_candidatesreceivesargs=[]→ the positionalreferenceis never a candidate (the kwarg spellingfile="…"IS blocked; only the positional escapes). - Sink:
repo.git.tag(*args, **kwargs)@ tag.py:158 → no--. argv (observed):['git','tag','-f','vpwn','--file=<secret>']. - Impact: annotated tag created;
tagref.tag.message== file contents (arbitrary file read).
Bypass Evidence
Independently reproduced (independent test harness, git 2.43.0, default allow_unsafe_options=False): TagReference.create(repo,'vp','--file=<secret>') → PASSED; tag.message == 'GATE_SECRET_LINE_A\nGATE_SECRET_LINE_B'. Control: TagReference.create(..., file='<secret>') → UnsafeOptionError: --file is not allowed. Fix-commit read: 3af0c251 adds _option_candidates([], kwargs) (empty args → positional never a candidate).
Affected Versions
GitPython <= 3.1.58 (sink present verbatim on the latest release tag; git diff 3.1.57..HEAD touches only test files).
Suggested Fix
Include the positional reference (and path) in the option-candidate list passed to check_unsafe_options, or place a -- separator before the positional arguments in TagReference.create().
Reported by zx (Jace) — GitHub: @manus-use
Ссылки
- https://github.com/gitpython-developers/GitPython/security/advisories/GHSA-3wxw-xv34-2frg
- https://nvd.nist.gov/vuln/detail/CVE-2026-78679
- https://github.com/gitpython-developers/GitPython/pull/2208
- https://github.com/gitpython-developers/GitPython/commit/1b0d2d9b91575f7db44ef4ff58ac37fc9335e5f6
- https://github.com/gitpython-developers/GitPython/releases/tag/3.1.59
- https://www.vulncheck.com/advisories/gitpython-before-arbitrary-file-read-via-tagreference-create
Пакеты
GitPython
<= 3.1.58
3.1.59
Связанные уязвимости
GitPython before 3.1.59 contains an arbitrary file read vulnerability in TagReference.create() where a positional reference parameter bypasses the unsafe option guard. Attackers can supply a reference value like --file=<path> to read arbitrary files, with contents returned in the annotated tag message.
GitPython before 3.1.59 contains an arbitrary file read vulnerability in TagReference.create() where a positional reference parameter bypasses the unsafe option guard. Attackers can supply a reference value like --file=<path> to read arbitrary files, with contents returned in the annotated tag message.
GitPython before 3.1.59 contains an arbitrary file read vulnerability in TagReference.create() where a positional reference parameter bypasses the unsafe option guard. Attackers can supply a reference value like --file=<path> to read arbitrary files, with contents returned in the annotated tag message.
GitPython before 3.1.59 contains an arbitrary file read vulnerability ...