CVE-2025-63650
📋 TL;DR
An out-of-bounds read vulnerability in Monkey web server's memory handling allows attackers to cause denial of service by sending crafted HTTP requests. This affects Monkey web server users running vulnerable versions, potentially disrupting web services.
💻 Affected Systems
- Monkey web server
⚠️ Risk & Real-World Impact
Worst Case
Complete service disruption making the web server unavailable to legitimate users
Likely Case
Service crashes or becomes unresponsive requiring manual restart
If Mitigated
Minimal impact with proper network controls and monitoring
🎯 Exploit Status
Crafting malicious HTTP requests requires minimal technical skill
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Versions after commit f37e984
Vendor Advisory: https://github.com/archersec/security-advisories/blob/master/monkey/monkey-advisory-2025.md
Restart Required: Yes
Instructions:
1. Update Monkey to latest version 2. Restart Monkey service 3. Verify fix with test requests
🔧 Temporary Workarounds
Network filtering
allBlock suspicious HTTP requests at network perimeter
Rate limiting
allImplement request rate limiting to reduce attack surface
🧯 If You Can't Patch
- Implement WAF rules to filter malicious HTTP patterns
- Isolate vulnerable servers behind reverse proxies with request validation
🔍 How to Verify
Check if Vulnerable:
Check Monkey version and compare with vulnerable commit rangeCheck Version:
monkey --version or check build commit hashVerify Fix Applied:
Test with crafted HTTP requests and monitor for crashes📡 Detection & Monitoring
Log Indicators:
- Unexpected server crashes
- Memory access error logs
- Malformed HTTP request patterns
Network Indicators:
- HTTP requests with unusual headers or payloads
- Multiple connection attempts to trigger crash
SIEM Query:
source="monkey" AND (event="crash" OR error="memory" OR error="segfault")