CVE-2015-8969
📋 TL;DR
CVE-2015-8969 is a command injection vulnerability in git-fastclone that allows attackers to execute arbitrary shell commands by manipulating arguments passed to 'cd' and 'git clone' commands. This affects users of git-fastclone versions before 1.0.5 who process untrusted input through the library.
💻 Affected Systems
- git-fastclone
📦 What is this software?
Git Fastclone by Squareup
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise with remote code execution, allowing attackers to install malware, exfiltrate data, or pivot to other systems.
Likely Case
Local privilege escalation or arbitrary command execution in CI/CD pipelines where git-fastclone processes untrusted repository URLs or paths.
If Mitigated
Limited impact if input validation and proper sandboxing prevent command injection attempts.
🎯 Exploit Status
Exploitation requires ability to control input to git-fastclone commands. Proof-of-concept available in security reports.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.0.5
Vendor Advisory: https://github.com/square/git-fastclone/pull/5
Restart Required: No
Instructions:
1. Update git-fastclone to version 1.0.5 or later. 2. Run: gem update git-fastclone 3. Verify installation with: gem list git-fastclone
🔧 Temporary Workarounds
Input validation wrapper
allImplement strict input validation for all arguments passed to git-fastclone
# Validate repository URLs before passing to git-fastclone
# Example: Use regex to validate URL format
if [[ ! $REPO_URL =~ ^https://github\.com/[a-zA-Z0-9_-]+/[a-zA-Z0-9_-]+(\.git)?$ ]]; then
echo 'Invalid repository URL'
exit 1
fi
Sandbox execution
linuxRun git-fastclone in restricted environments
# Use Docker with minimal privileges
docker run --rm -v $(pwd):/work -w /work alpine/git clone [REPO]
# Or use chroot/sandbox tools
🧯 If You Can't Patch
- Discontinue use of git-fastclone and switch to native git commands with proper input validation.
- Implement network segmentation to isolate systems using git-fastclone from sensitive resources.
🔍 How to Verify
Check if Vulnerable:
Check git-fastclone version: gem list git-fastclone | grep fastclone. If version is less than 1.0.5, system is vulnerable.Check Version:
gem list git-fastclone | grep fastcloneVerify Fix Applied:
After updating, verify version is 1.0.5 or higher: gem list git-fastclone | grep -E 'fastclone \(1\.0\.[5-9]|1\.[1-9]'📡 Detection & Monitoring
Log Indicators:
- Unusual shell commands executed during git operations
- git-fastclone processes with suspicious arguments
- Failed command execution attempts in system logs
Network Indicators:
- Unexpected outbound connections from CI/CD systems
- Data exfiltration patterns from git servers
SIEM Query:
process.name:"git-fastclone" AND cmdline:"cd *" OR cmdline:"git clone *" AND NOT user:trusted_user