Path Traversal in Git git apply

This repository is a small Bash-based proof of concept for CVE-2023-23946 in Git. It contains two files: a README describing the vulnerability and usage, and a single executable script, exploit.sh, which is the main exploit logic. The script is interactive: it asks the operator for a target directory to symlink, a filename to create under that directory, and arbitrary file contents to embed in the patch. It then creates a temporary repository under /tmp/cve_git_patch, initializes Git, commits a symlink pointing to the chosen target directory, and generates a malicious patch file named exploit.patch. The patch performs a rename from symlink to renamed-symlink and adds a new file beneath the renamed symlink path, causing vulnerable Git patch handling to write attacker-controlled content into the symlink target when applied by the victim. The printed example command shows the intended abuse path: a different user runs /usr/bin/git apply against the crafted patch, potentially enabling local privilege abuse or lateral access, such as planting an SSH authorized_keys file. There are no network callbacks or remote C2 endpoints in the exploit itself; it is a local file-manipulation exploit that weaponizes Git patch application behavior.

This repository provides a proof-of-concept (POC) exploit for CVE-2023-23946, a vulnerability in git's handling of symbolic links. The exploit consists of a README.md explaining the vulnerability and exploitation steps, and an 'exploit.patch' file that demonstrates the attack. The attack involves creating a symbolic link in the repository that points outside the working tree, then applying a crafted patch that renames the symlink and writes arbitrary content to a file outside the repository. This leverages git's improper protections against symlink manipulation during patch application, allowing an attacker to write to arbitrary files on the filesystem. The exploit is local in nature and requires the attacker to have access to a vulnerable git repository. The main fingerprintable endpoint is the file path outside the working tree that the attacker targets for writing.