Signature Detail
Short Name |
TCP:S2C:EVASION:S2C-ESTB-SYN |
|---|---|
Severity |
Low |
Recommended |
No |
Category |
TCP |
Release Date |
2003/04/22 |
Update Number |
1213 |
Supported Platforms |
idp-4.0+, isg-3.0+, j-series-9.5+, mx-9.4+, srx-9.2+, srx-branch-9.4+, vsrx-12.1+ |
TCP: S2C Evasion SYN in ESTABLISHED State
This protocol anomaly triggers when it detects a SYN packet while a flow is in the ESTABLISHED state. Because IDP can determine what the receiving host does with these abnormal packets, it is safe to permit them.
Extended Description
A TCP packet that has the SYN flag set after the initial SYN packet has been transmitted constitutes a protocol anomaly. Detection of this condition could indicate a network configuration error, or that malicious activity involving the injection of malformed IP packets is underway.
References