CVE-2022-1537
📋 TL;DR
CVE-2022-1537 is a Time-of-Check Time-of-Use (TOCTOU) race condition vulnerability in GruntJS's file.copy operations that allows arbitrary file writes. This affects GruntJS users who run file.copy operations with elevated privileges. Attackers with write access to both source and destination directories can exploit this to write arbitrary files, potentially leading to privilege escalation.
💻 Affected Systems
- GruntJS
📦 What is this software?
Grunt by Gruntjs
⚠️ Risk & Real-World Impact
Worst Case
Local privilege escalation to root if GruntJS runs as root, allowing attackers to replace critical system files like /etc/shadow or modify user configuration files like .bashrc.
Likely Case
Arbitrary file writes within the GruntJS user's privilege context, potentially leading to code execution, data manipulation, or lateral movement within the affected environment.
If Mitigated
Limited to file writes within the GruntJS user's permissions if proper access controls and privilege separation are implemented.
🎯 Exploit Status
Exploitation requires local access and write permissions to relevant directories. Race condition timing makes exploitation somewhat complex but demonstrated in public disclosures.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.5.3
Vendor Advisory: https://github.com/gruntjs/grunt/commit/58016ffac5ed9338b63ecc2a63710f5027362bae
Restart Required: No
Instructions:
1. Update GruntJS to version 1.5.3 or later using npm: npm update grunt@latest
2. Verify the update with: npm list grunt
3. No restart required as this is a library update.
🔧 Temporary Workarounds
Avoid file.copy with elevated privileges
allRun GruntJS with minimal necessary privileges and avoid using file.copy operations with root or elevated user permissions.
Use alternative file operations
allReplace vulnerable file.copy operations with safer alternatives or implement additional validation checks in custom tasks.
🧯 If You Can't Patch
- Implement strict file system permissions to limit write access to source and destination directories
- Run GruntJS with the lowest possible privilege level, never as root
🔍 How to Verify
Check if Vulnerable:
Check GruntJS version: npm list grunt | grep grunt. If version is below 1.5.3, the system is vulnerable.Check Version:
npm list grunt | grep gruntVerify Fix Applied:
After updating, verify version is 1.5.3 or higher: npm list grunt | grep grunt📡 Detection & Monitoring
Log Indicators:
- Unusual file copy operations in GruntJS logs
- Permission denied errors followed by successful file operations
Network Indicators:
- None - this is a local file system vulnerability
SIEM Query:
Process execution logs showing GruntJS file.copy operations with elevated privileges, especially when followed by unexpected file modifications🔗 References
- https://github.com/gruntjs/grunt/commit/58016ffac5ed9338b63ecc2a63710f5027362bae
- https://huntr.dev/bounties/0179c3e5-bc02-4fc9-8491-a1a319b51b4d
- https://lists.debian.org/debian-lts-announce/2023/04/msg00006.html
- https://github.com/gruntjs/grunt/commit/58016ffac5ed9338b63ecc2a63710f5027362bae
- https://huntr.dev/bounties/0179c3e5-bc02-4fc9-8491-a1a319b51b4d
- https://lists.debian.org/debian-lts-announce/2023/04/msg00006.html
