CVE-2023-4914
📋 TL;DR
This vulnerability allows attackers to perform relative path traversal attacks in Cecil static site generator. By manipulating file paths, attackers can read, write, or delete files outside the intended directory. Users running Cecil versions prior to 7.47.1 are affected.
💻 Affected Systems
- Cecil static site generator
📦 What is this software?
Cecil by Cecil
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise through arbitrary file read/write/delete, potentially leading to remote code execution, data exfiltration, or system destruction.
Likely Case
Unauthorized access to sensitive files (configuration files, source code, credentials) or modification/deletion of website content.
If Mitigated
Limited impact with proper file system permissions and input validation in place, potentially only affecting non-critical files.
🎯 Exploit Status
Path traversal vulnerabilities are well-understood and easy to exploit. Public proof-of-concept exists in the bounty report.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 7.47.1
Vendor Advisory: https://github.com/cecilapp/cecil/commit/00dc79f10ce723034b7140d79f4ac731d1d902eb
Restart Required: No
Instructions:
1. Update Cecil using Composer: composer update cecil/cecil 2. Verify version: cecil --version should show 7.47.1 or higher 3. Rebuild your static site if needed
🔧 Temporary Workarounds
Input validation wrapper
allImplement custom validation for all user-supplied file paths before passing to Cecil
# Custom PHP validation function to sanitize paths
# Ensure paths don't contain ../ or similar traversal sequences
File system restrictions
linuxRun Cecil with restricted file system permissions and in chroot/jail environment
# Run as non-root user with minimal permissions
# Use Docker with read-only volumes where possible
🧯 If You Can't Patch
- Disable any functionality that accepts user-controlled file paths
- Implement strict input validation and path normalization for all file operations
🔍 How to Verify
Check if Vulnerable:
Run: cecil --version and check if version is below 7.47.1Check Version:
cecil --versionVerify Fix Applied:
Run: cecil --version and confirm version is 7.47.1 or higher. Test with known path traversal payloads.📡 Detection & Monitoring
Log Indicators:
- Unusual file access patterns
- Failed attempts to access files outside web root
- Multiple ../ sequences in file paths
Network Indicators:
- HTTP requests containing ../ sequences in parameters
- Unexpected file downloads/uploads
SIEM Query:
source="cecil" AND ("../" OR "..\" OR "%2e%2e%2f")