CVE-2024-37826
📋 TL;DR
A NULL pointer dereference vulnerability in vercot Serva v4.6.0 allows attackers to crash the service via specially crafted HTTP requests, causing denial of service. This affects systems running the vulnerable version of vercot Serva HTTP server software.
💻 Affected Systems
- vercot Serva
📦 What is this software?
Serva by Vercot
⚠️ Risk & Real-World Impact
Worst Case
Complete service outage requiring manual restart, potentially disrupting critical services that depend on the HTTP server.
Likely Case
Service crash and temporary unavailability until automatic or manual restart occurs.
If Mitigated
Minimal impact with proper monitoring and automated restart mechanisms in place.
🎯 Exploit Status
The GitHub gist contains proof-of-concept code demonstrating the vulnerability.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: v4.6.1 or later
Vendor Advisory: https://github.com/vercot/serva/releases
Restart Required: Yes
Instructions:
1. Download latest version from GitHub releases. 2. Stop vercot Serva service. 3. Replace binary with patched version. 4. Restart service.
🔧 Temporary Workarounds
HTTP Request Filtering
allImplement web application firewall or reverse proxy to filter malformed HTTP requests.
Service Monitoring and Auto-restart
linuxConfigure monitoring to detect service crashes and automatically restart.
systemctl enable serva
systemctl start serva
🧯 If You Can't Patch
- Implement network segmentation to restrict access to vercot Serva instances
- Deploy intrusion detection systems to monitor for exploitation attempts
🔍 How to Verify
Check if Vulnerable:
Check vercot Serva version; if it's exactly 4.6.0, it's vulnerable.Check Version:
serva --version or check service propertiesVerify Fix Applied:
Verify version is 4.6.1 or later and test with normal HTTP requests.📡 Detection & Monitoring
Log Indicators:
- Unexpected service termination
- NULL pointer exception in logs
- HTTP request causing crash
Network Indicators:
- Malformed HTTP requests to vercot Serva port
- Sudden drop in HTTP responses
SIEM Query:
source="vercot.log" AND ("crash" OR "terminated" OR "NULL pointer")