Last Modified: Apr 28, 2025
Affected Product(s):
BIG-IP AFM, LTM
Known Affected Versions:
12.1.0, 12.1.0 HF1, 12.1.0 HF2, 12.1.1, 12.1.1 HF1, 12.1.1 HF2, 12.1.2, 12.1.2 HF1, 12.1.2 HF2, 12.1.3, 12.1.3.1, 12.1.3.2, 12.1.3.3, 12.1.3.4, 12.1.3.5, 12.1.3.6, 12.1.3.7, 12.1.4, 12.1.4.1, 12.1.5, 12.1.5.1, 12.1.5.2, 12.1.5.3, 12.1.6, 13.0.0, 13.0.0 HF1, 13.0.0 HF2, 13.0.0 HF3, 13.0.1, 13.1.0, 13.1.0.1, 13.1.0.2, 13.1.0.3, 13.1.0.4, 13.1.0.5, 13.1.0.6, 13.1.0.7, 13.1.0.8, 13.1.1, 13.1.1.2, 13.1.1.3, 13.1.1.4, 13.1.1.5, 13.1.3, 13.1.3.1, 13.1.3.2, 13.1.3.3, 13.1.3.4, 13.1.3.5, 13.1.3.6, 13.1.4, 13.1.4.1, 13.1.5, 13.1.5.1
Fixed In:
14.0.0
Opened: Jan 17, 2018 Severity: 2-Critical
TCP handshake rejected if SYN cookies attack is detected on platforms with some multiple HSB devices and BIG-IP Virtual Edition (VE) environments. OR TCP handshake is accepted, but the client-side MSS is not set properly, resulting in BIG-IP sending oversized frames on-wire.
Regular traffic gets reset because of handshake failures. OR BIG-IP is sending oversized packets, exceeding MSS.
Enable syncookie protection in LTM global setting, and start SYN flood attacks.
Turn off syncookie protection.
Revised the syncookie lifetime check logic to better cope with the multi-HSB cases. Added VE syncookie handling code that is compatible with the multi-HSB per tmm platforms.