CVE-2024-55553
📋 TL;DR
This vulnerability in FRRouting (FRR) allows attackers to trigger continuous route re-validation by sending RTR updates exceeding the socket buffer size. This can degrade routing performance globally for FRR instances using RPKI, potentially causing routing instability. All FRR deployments from version 6.0 onward using RTR/RPKI are affected.
💻 Affected Systems
- FRRouting (FRR)
⚠️ 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
Continuous route re-validation causes severe routing performance degradation, potentially leading to network instability, dropped routes, and denial of service for FRR routers globally using RPKI.
Likely Case
Periodic performance degradation during RTR updates, increased CPU/memory usage, and heightened BMP traffic to monitoring systems.
If Mitigated
Minimal impact with proper network segmentation and monitoring, though organic occurrences may still cause brief performance spikes.
🎯 Exploit Status
Exploitation requires sending RTR updates exceeding buffer size, which can be done remotely via RTR protocol. No authentication needed.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 10.0.3, 10.1.2, 10.2.1, or 10.3 and later
Vendor Advisory: https://frrouting.org/security/cve-2024-55553/
Restart Required: Yes
Instructions:
1. Identify current FRR version. 2. Upgrade to patched version: 10.0.3, 10.1.2, 10.2.1, or 10.3+. 3. Restart FRR service. 4. Verify fix with version check.
🔧 Temporary Workarounds
Increase socket buffer size
LinuxIncrease the OS socket buffer size beyond default 4K to reduce likelihood of buffer overflow
sysctl -w net.core.rmem_max=65536
sysctl -w net.core.wmem_max=65536
Limit RTR connections
LinuxRestrict RTR connections to trusted sources using firewall rules
iptables -A INPUT -p tcp --dport 323 -s trusted_ip -j ACCEPT
iptables -A INPUT -p tcp --dport 323 -j DROP
🧯 If You Can't Patch
- Implement strict network segmentation to isolate RTR traffic to trusted sources only
- Deploy network monitoring to detect abnormal RTR update patterns and rate limit suspicious traffic
🔍 How to Verify
Check if Vulnerable:
Check FRR version: if between 6.0 and 10.2.x (excluding 10.0.3, 10.1.2, 10.2.1) and RTR is enabled, system is vulnerableCheck Version:
frr --versionVerify Fix Applied:
Verify FRR version shows 10.0.3, 10.1.2, 10.2.1, or 10.3+ and monitor for abnormal route re-validation events📡 Detection & Monitoring
Log Indicators:
- Frequent 'route re-validation' messages in FRR logs
- Unusual RTR update frequency in logs
- High CPU usage during RTR updates
Network Indicators:
- Abnormally high RTR traffic volume
- Increased BMP traffic to monitoring systems
- Routing instability during RTR update intervals
SIEM Query:
source="frr.log" AND "re-validation" OR "RTR update" frequency > threshold