CVE-2025-24934
📋 TL;DR
This vulnerability allows spoofing attacks against applications using SO_REUSEPORT_LB sockets in FreeBSD. When a socket is connected to a specific host but also belongs to a load-balancing group, it incorrectly receives packets from any host, violating the connection contract. This affects FreeBSD systems running vulnerable kernel versions with applications using SO_REUSEPORT_LB sockets.
💻 Affected Systems
- FreeBSD kernel
⚠️ 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
Attackers could spoof packets to appear as legitimate traffic, potentially leading to data injection, session hijacking, or disruption of network services relying on connected sockets.
Likely Case
Network applications receiving unexpected packets from unauthorized sources, potentially causing application errors, data corruption, or information disclosure.
If Mitigated
With proper network segmentation and firewall rules, impact is limited to internal network segments where attackers have access.
🎯 Exploit Status
Exploitation requires understanding of socket programming and network access to target system. No public exploits known at this time.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: FreeBSD 14.1-RELEASE-p1, 14.2-RELEASE-p1, 14.3-RELEASE-p1, 15.0-RELEASE-p1
Vendor Advisory: https://security.freebsd.org/advisories/FreeBSD-SA-25:09.netinet.asc
Restart Required: No
Instructions:
1. Update FreeBSD system using 'freebsd-update fetch' and 'freebsd-update install'. 2. Rebuild and reinstall any custom kernel if using one. 3. No reboot required for runtime fix, but affected applications may need restart.
🔧 Temporary Workarounds
Avoid SO_REUSEPORT_LB on connected sockets
allModify applications to not use SO_REUSEPORT_LB socket option on sockets that will be connected to specific hosts.
🧯 If You Can't Patch
- Implement strict network segmentation to limit which hosts can communicate with affected services
- Use firewall rules to restrict incoming traffic to expected source addresses for connected sockets
🔍 How to Verify
Check if Vulnerable:
Check FreeBSD version with 'uname -a'. If running affected versions (14.1, 14.2, 14.3, 15.0 without patch) and applications use SO_REUSEPORT_LB, system is vulnerable.Check Version:
uname -aVerify Fix Applied:
Verify FreeBSD version is patched: 'uname -a' should show -p1 suffix. Check that applications using SO_REUSEPORT_LB no longer receive unexpected packets.📡 Detection & Monitoring
Log Indicators:
- Application logs showing unexpected packet sources
- Network service errors or unexpected behavior
Network Indicators:
- Unexpected source IPs communicating with connected sockets
- Spoofed packets reaching services
SIEM Query:
Network traffic from unexpected sources to services known to use SO_REUSEPORT_LB sockets