CVE-2025-29908
📋 TL;DR
This vulnerability allows remote attackers to cause a Hash DoS attack by initiating QUIC connections with colliding Source Connection IDs, leading to high CPU consumption on affected Netty QUIC servers. It affects systems using Netty QUIC codec versions before 0.0.71.Final. The attack requires network access to the vulnerable service.
💻 Affected Systems
- Netty QUIC codec (netty-incubator-codec-quic)
⚠️ 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 degradation or denial of service due to 100% CPU utilization, making the server unresponsive to legitimate traffic.
Likely Case
Significant performance degradation and increased latency for legitimate connections, potentially causing partial service disruption.
If Mitigated
Minimal impact with proper rate limiting and monitoring in place, though some performance degradation may still occur during attacks.
🎯 Exploit Status
The advisory includes technical details and the attack requires sending specially crafted QUIC connection requests.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 0.0.71.Final
Vendor Advisory: https://github.com/netty/netty-incubator-codec-quic/security/advisories/GHSA-hqqc-jr88-p6x2
Restart Required: Yes
Instructions:
1. Update Netty QUIC codec dependency to version 0.0.71.Final or later. 2. Rebuild and redeploy affected applications. 3. Restart services using the updated library.
🔧 Temporary Workarounds
Rate limit QUIC connections
allImplement connection rate limiting to reduce impact of hash collision attacks
# Configure rate limiting in application or network firewall
Disable QUIC if not required
allDisable QUIC protocol support if not essential for application functionality
# Disable QUIC in application configuration
🧯 If You Can't Patch
- Implement strict network segmentation to limit QUIC traffic to trusted sources only
- Deploy DDoS protection services with QUIC protocol awareness
🔍 How to Verify
Check if Vulnerable:
Check Netty QUIC codec version in your application dependencies or build configurationCheck Version:
Check build.gradle, pom.xml, or dependency manifest for netty-incubator-codec-quic versionVerify Fix Applied:
Verify Netty QUIC codec version is 0.0.71.Final or later after update📡 Detection & Monitoring
Log Indicators:
- Unusual high CPU usage patterns
- Increased QUIC connection attempts
- Connection timeouts or failures
Network Indicators:
- Spike in QUIC connection requests from single or multiple sources
- Abnormal QUIC packet patterns
SIEM Query:
source="application_logs" AND ("QUIC" OR "netty-quic") AND (cpu_usage > 90 OR connection_count > threshold)