CVE-2025-59147
📋 TL;DR
CVE-2025-59147 is a detection bypass vulnerability in Suricata where crafted traffic with multiple SYN packets containing different sequence numbers within the same flow tuple can cause Suricata to fail to track TCP sessions. This allows attackers to evade detection in IDS mode or cause flow blocking in IPS mode. Organizations running Suricata 7.0.11 and below or 8.0.0 are affected.
💻 Affected Systems
- Suricata
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete network intrusion detection bypass allowing malicious traffic to pass undetected, potentially enabling data exfiltration, malware delivery, or lateral movement without alerting security teams.
Likely Case
Selective detection bypass for specific TCP-based attacks that can be crafted to exploit this session tracking flaw, reducing security monitoring effectiveness.
If Mitigated
Minimal impact with proper network segmentation, additional security layers, and updated Suricata versions preventing the bypass technique.
🎯 Exploit Status
Exploitation requires network access to send crafted TCP packets but no authentication or special privileges. The technique is straightforward for attackers with network packet crafting capabilities.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 7.0.12, 8.0.1
Vendor Advisory: https://github.com/OISF/suricata/security/advisories/GHSA-v8hv-6v7x-4c2r
Restart Required: Yes
Instructions:
1. Backup current Suricata configuration. 2. Stop Suricata service. 3. Update to Suricata 7.0.12 or 8.0.1 using package manager or source compilation. 4. Verify configuration compatibility. 5. Start Suricata service. 6. Monitor logs for proper operation.
🔧 Temporary Workarounds
IPS Mode Enforcement
allConfigure Suricata to run in IPS mode where this vulnerability causes blocking rather than silent bypass, though this changes operational behavior.
suricata -c /etc/suricata/suricata.yaml --ips
🧯 If You Can't Patch
- Implement network segmentation to limit exposure of critical assets
- Deploy complementary network monitoring solutions to detect anomalous TCP behavior
🔍 How to Verify
Check if Vulnerable:
Check Suricata version with 'suricata --build-info' or 'suricata -V' and compare against affected versions 7.0.11 and below or 8.0.0.Check Version:
suricata -VVerify Fix Applied:
After updating, verify version shows 7.0.12 or 8.0.1 and test with known TCP session tracking test traffic.📡 Detection & Monitoring
Log Indicators:
- Missing expected detection alerts for known malicious traffic
- Unusual TCP session establishment patterns in flow logs
Network Indicators:
- Multiple SYN packets with varying sequence numbers from same source to same destination
- Abnormal TCP handshake patterns bypassing normal session tracking
SIEM Query:
source="suricata" (event_type="alert" AND NOT alert.signature=*) | stats count by src_ip, dest_ip, dest_port🔗 References
- https://forum.suricata.io/t/suricata-8-0-1-and-7-0-12-released/6018
- https://github.com/OISF/suricata/commit/be6315dba0d9101b11d16e9dacfe2822b3792f1b
- https://github.com/OISF/suricata/commit/e91b03c90385db15e21cf1a0e85b921bf92b039e
- https://github.com/OISF/suricata/security/advisories/GHSA-v8hv-6v7x-4c2r
