CVE-2023-50965
📋 TL;DR
This vulnerability in MicroHttpServer allows attackers to trigger a stack-based buffer overflow by sending an excessively long URI. This can lead to remote code execution on affected systems. Anyone running vulnerable versions of MicroHttpServer is at risk.
💻 Affected Systems
- MicroHttpServer (Micro HTTP Server)
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Full system compromise with remote code execution leading to data theft, malware deployment, or complete system takeover.
Likely Case
Service disruption, denial of service, or limited code execution depending on exploit implementation and system protections.
If Mitigated
Denial of service or application crash if exploit attempts are blocked by security controls.
🎯 Exploit Status
The vulnerability is straightforward to exploit with publicly available details and proof-of-concept.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Versions after commit 4398570
Vendor Advisory: https://github.com/starnight/MicroHttpServer/issues/5
Restart Required: Yes
Instructions:
1. Update to the latest version from the official GitHub repository. 2. Rebuild and redeploy the application. 3. Restart the MicroHttpServer service.
🔧 Temporary Workarounds
URI Length Restriction
allImplement a reverse proxy or web application firewall to restrict URI length to prevent buffer overflow.
nginx: client_max_body_size 1k;
apache: LimitRequestLine 1024
Network Segmentation
linuxIsolate MicroHttpServer instances from untrusted networks and restrict access to trusted IPs only.
iptables -A INPUT -p tcp --dport [PORT] -s [TRUSTED_IP] -j ACCEPT
iptables -A INPUT -p tcp --dport [PORT] -j DROP
🧯 If You Can't Patch
- Deploy a web application firewall (WAF) with buffer overflow protection rules.
- Implement network segmentation and restrict access to only necessary users/systems.
🔍 How to Verify
Check if Vulnerable:
Check if running MicroHttpServer version includes commit 4398570 or earlier. Review source code for vulnerable _ReadStaticFiles function.Check Version:
Check git commit history or version metadata in the application.Verify Fix Applied:
Verify the application has been updated to a version after commit 4398570 and test with long URI requests.📡 Detection & Monitoring
Log Indicators:
- Unusually long URI requests in access logs
- Application crash logs referencing buffer overflow
Network Indicators:
- HTTP requests with URI length exceeding normal thresholds
- Repeated long URI attempts from single sources
SIEM Query:
source="web_logs" AND uri_length>1024