CVE-2025-71031
📋 TL;DR
CVE-2025-71031 is a denial-of-service vulnerability in Water-Melon Melon's HTTP component that lacks request header length limits. Attackers can crash affected systems by sending excessively large HTTP headers that consume all available RAM. This affects any system running vulnerable versions of the Water-Melon Melon library.
💻 Affected Systems
- Water-Melon Melon
⚠️ Risk & Real-World Impact
Worst Case
Complete system unavailability due to memory exhaustion, potentially requiring manual intervention to restart services.
Likely Case
Service disruption affecting availability of applications using the vulnerable library.
If Mitigated
Minimal impact with proper request filtering and memory limits in place.
🎯 Exploit Status
Simple HTTP request with oversized headers can trigger the vulnerability.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown
Vendor Advisory: None found
Restart Required: Yes
Instructions:
1. Monitor for official patch from Water-Melon Melon maintainers
2. Apply patch when available
3. Restart affected services
🔧 Temporary Workarounds
HTTP Request Header Size Limiting
allImplement request header size limits at reverse proxy or load balancer level
# nginx example: add to server block
client_header_buffer_size 4k;
large_client_header_buffers 4 8k;
# Apache example: add to config
LimitRequestFieldSize 8190
Memory Usage Monitoring
linuxImplement monitoring and alerting for abnormal memory consumption
# Monitor process memory usage
top -b -n 1 | grep melon
# Set up alerts for high memory usage
🧯 If You Can't Patch
- Deploy Web Application Firewall (WAF) with HTTP header size limiting rules
- Isolate vulnerable systems behind reverse proxies with request size limits
🔍 How to Verify
Check if Vulnerable:
Check if using Water-Melon Melon commit 9df9292 or earlier. Review source code for lack of HTTP header length validation.Check Version:
# Check git commit hash
git log --oneline -1Verify Fix Applied:
Test with oversized HTTP headers after applying workarounds to ensure system remains responsive.📡 Detection & Monitoring
Log Indicators:
- Abnormally large HTTP requests
- Memory exhaustion errors
- Process crashes/restarts
Network Indicators:
- HTTP requests with extremely large headers
- Repeated connection attempts with varying header sizes
SIEM Query:
source="web_logs" AND (request_size>10000 OR header_length>8000)