CVE-2023-54339
📋 TL;DR
CVE-2023-54339 is a remote command execution vulnerability in Webgrind 1.1 that allows unauthenticated attackers to inject and execute arbitrary OS commands via the dataFile parameter in index.php. This affects any system running the vulnerable version of Webgrind, potentially compromising the entire server.
💻 Affected Systems
- Webgrind
📦 What is this software?
Webgrind by Webgrind Project
⚠️ Risk & Real-World Impact
Worst Case
Attackers gain full control of the server, leading to data theft, ransomware deployment, or use as a pivot point for further attacks.
Likely Case
Attackers execute commands to steal sensitive data, install backdoors, or disrupt services.
If Mitigated
Impact is limited to the Webgrind application context if proper isolation (e.g., containerization) is in place.
🎯 Exploit Status
Exploits are publicly available, making this easy to weaponize with minimal skill required.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Not available
Vendor Advisory: No official vendor advisory found
Restart Required: No
Instructions:
No official patch exists; consider upgrading to a newer version if available, or apply workarounds.
🔧 Temporary Workarounds
Input Validation and Sanitization
allModify index.php to validate and sanitize the dataFile parameter, rejecting any input containing shell metacharacters.
Edit index.php to add input filtering, e.g., using escapeshellarg() in PHP.
Web Application Firewall (WAF) Rule
allDeploy a WAF rule to block requests containing suspicious patterns in the dataFile parameter.
Configure WAF to block patterns like '&', ';', or command injection attempts.
🧯 If You Can't Patch
- Isolate the Webgrind instance in a restricted network segment or container to limit blast radius.
- Disable or remove Webgrind if not essential, and monitor for exploitation attempts.
🔍 How to Verify
Check if Vulnerable:
Test by sending a crafted request to index.php with a malicious dataFile parameter and observe if commands execute.Check Version:
Check the Webgrind version in the source code or configuration files.Verify Fix Applied:
After applying workarounds, retest the exploit to ensure command execution is blocked.📡 Detection & Monitoring
Log Indicators:
- Unusual HTTP requests to index.php with dataFile parameter containing shell metacharacters or command strings.
Network Indicators:
- Outbound connections from the Webgrind server to unknown IPs post-exploit.
SIEM Query:
Search for logs with 'dataFile' parameter and patterns like '&calc.exe' or similar injection attempts.