high

GHSA-jm78-9fvv-mhgr

PyPI · GitPython

Summary

GitPython: git-config OPTION-name injection via =/#/whitespace bypasses name validator, enabling forged core.sshCommand/hooksPath (RCE)

Severity
high
CVSS
8.8
CWE
CWE-74, CWE-88
Published
2026-08-07
Updated
2026-08-07

Advisory details

Summary

GitPython's config-name validator only neutralizes CR/LF/NUL for the "option" label; it does not reject =, #, ;, [, ], or whitespace in an option name. write_section writes the option name verbatim into the config file, so an option name such as sshCommand = touch <cmd> # is written as \tsshCommand = touch <cmd> # = <value>, which git parses as core.sshCommand = touch <cmd> (the trailing # comments out the intended value). This forges arbitrary config directives (core.sshCommand, core.hooksPath, alias.*) → RCE on the next git operation. This is a distinct field (option name, not section name) and distinct character class (=/#/space, not newline/bracket) from GHSA-3rp5-jjmw-4wv2 (section-name bracket injection) and GHSA-mv93-w799-cj2w / GHSA-v87r-6q3f-2j67 (newline injection).

Root Cause

_assure_config_name_safe(name, label) (git/config.py:897) applies the bracket/quote state machine ONLY when label == "section"; for the "option" label it falls through with just the UNSAFE_CONFIG_CHARS_RE = [\r\n\x00] regex. write_section then writes the option name verbatim into "\t%s = %s\n" (config.py:702).

Impact

Arbitrary git-config directive injection → remote code execution via core.sshCommand (fires on any ssh git operation, no staged file needed) or core.hooksPath (with a staged hook). Requires the embedding application to forward a caller-influenced OPTION NAME into the config writer (name-control model, the same name-control model accepted by the related published advisories GHSA-3rp5-jjmw-4wv2 and GHSA-mv93-w799-cj2w). Default configuration.

Proof of Concept

with repo.config_writer() as cw:
    cw.set_value("core", "sshCommand = touch /tmp/RCE #", "x")
# git config --get core.sshCommand  ->  touch /tmp/RCE

Attack Chain

  1. Entry: app calls config writer with attacker-controlled OPTION name: set_value("core", "sshCommand = touch /tmp/RCE #", "x").
  2. Check: _assure_config_name_safe(option, "option") @ config.py. Guard: regex matches only [\r\n\x00]; bracket/quote state machine is gated on label=="section". Bypass proof: =,#,space pass → no ValueError.
  3. Sink: write_section writes "\tsshCommand = touch /tmp/RCE # = x\n" (config.py:702).
  4. Impact: git parses core.sshCommand=touch /tmp/RCE → arbitrary code execution on next git op.

Bypass Evidence

Independently reproduced (gate harness): set_value('core','sshCommand = touch <RCE> #','x') → no ValueError; file line sshCommand = touch <RCE> # = x; git config --get core.sshCommand → touch <RCE> (rc=0). Also verified core.hooksPath via both GitConfigParser and repo.config_writer(). Fix-commit read: bracket/quote checks are inside if label == "section"; the "option" label is not covered.

Affected Versions

GitPython <= 3.1.57 (validator present verbatim on the latest release tag).

Suggested Fix

Apply the section-name safety checks (reject =, #, ;, [, ], whitespace) to the "option" label as well, or validate the fully-rendered config line after substitution.

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.