CVE-2024-52811
📋 TL;DR
A heap buffer overflow vulnerability in ngtcp2's qlog functionality allows attackers to potentially execute arbitrary code or crash applications when qlog is enabled. This affects all users of ngtcp2 versions before 1.9.1 who have qlog enabled, though qlog is disabled by default. The vulnerability stems from improper validation of ACK frames before writing them to qlog.
💻 Affected Systems
- ngtcp2
⚠️ 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
Remote code execution leading to complete system compromise if qlog is enabled and the application runs with sufficient privileges.
Likely Case
Application crash (denial of service) due to heap corruption when qlog is enabled.
If Mitigated
No impact if qlog is disabled (default configuration).
🎯 Exploit Status
Exploitation requires qlog to be enabled and specific malformed ACK packets to trigger the integer underflow and buffer overflow.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.9.1
Vendor Advisory: https://github.com/ngtcp2/ngtcp2/security/advisories/GHSA-4gmv-gf46-r4g5
Restart Required: Yes
Instructions:
1. Upgrade ngtcp2 to version 1.9.1 or later. 2. Recompile any applications using ngtcp2. 3. Restart affected services.
🔧 Temporary Workarounds
Disable qlog
allEnsure qlog functionality is disabled in ngtcp2 configuration
Ensure ngtcp2 is configured with qlog disabled (default setting)
🧯 If You Can't Patch
- Ensure qlog functionality is completely disabled in all ngtcp2 configurations.
- Implement network filtering to block malformed QUIC packets if possible.
🔍 How to Verify
Check if Vulnerable:
Check if ngtcp2 version is below 1.9.1 and qlog is enabled in configuration.Check Version:
Check library version or application documentation for linked ngtcp2 versionVerify Fix Applied:
Verify ngtcp2 version is 1.9.1 or higher and applications have been recompiled with the updated library.📡 Detection & Monitoring
Log Indicators:
- Application crashes with heap corruption errors
- Memory access violation logs
Network Indicators:
- Malformed QUIC ACK packets with suspicious values
SIEM Query:
Search for process crashes related to ngtcp2 or QUIC handling applications