CVE-2025-41706
📋 TL;DR
This CVE describes a denial-of-service vulnerability in a webserver where an unauthenticated remote attacker can craft a special GET request with an over-long content-length header to crash or degrade the service. The vulnerability affects webservers with the specific vulnerable component, potentially impacting availability without compromising core functionality or data integrity.
💻 Affected Systems
- Specific webserver product not named in provided references
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Complete service outage causing unavailability of the webserver, potentially affecting dependent applications and users.
Likely Case
Temporary service degradation or crashes requiring manual restart, leading to intermittent availability issues.
If Mitigated
Minimal impact with proper network controls and monitoring in place to detect and block malicious requests.
🎯 Exploit Status
Exploitation requires crafting a specific HTTP GET request with manipulated content-length header, which is relatively straightforward.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Not specified in provided references
Vendor Advisory: https://certvde.com/de/advisories/VDE-2025-072
Restart Required: No
Instructions:
1. Check vendor advisory for specific patch information. 2. Apply the recommended security update. 3. Test the fix in a non-production environment first. 4. Deploy to production systems during maintenance windows.
🔧 Temporary Workarounds
Input Validation at Proxy/WAF
allConfigure web application firewall or reverse proxy to validate and reject HTTP requests with abnormally long content-length headers.
# Example for nginx: client_max_body_size 10m;
# Example for Apache: LimitRequestBody 10485760
Rate Limiting
allImplement rate limiting to prevent repeated exploitation attempts from single sources.
# Example for nginx: limit_req_zone $binary_remote_addr zone=one:10m rate=10r/s;
# Example for Apache: mod_ratelimit configuration
🧯 If You Can't Patch
- Implement network segmentation to isolate vulnerable systems from untrusted networks
- Deploy intrusion detection/prevention systems to monitor for exploitation attempts
🔍 How to Verify
Check if Vulnerable:
Test with crafted HTTP GET request containing abnormally long content-length header (e.g., Content-Length: 999999999999) and monitor server response.Check Version:
Check webserver version using appropriate command (e.g., httpd -v for Apache, nginx -v for nginx)Verify Fix Applied:
After patching, repeat the vulnerability test and verify the server handles the malformed request gracefully without crashing.📡 Detection & Monitoring
Log Indicators:
- HTTP requests with abnormally large content-length values
- Server crash/restart logs
- Error logs showing malformed request handling
Network Indicators:
- Unusual patterns of HTTP GET requests with manipulated headers
- Traffic spikes from single sources
SIEM Query:
source="webserver_logs" AND (content_length>100000000 OR http_status=400 OR http_status=413)