Bug ID 1692049: Modifying DOS TScookies impacts existing TCP connections with TCP TStamps enabled

Last Modified: Mar 26, 2025

Affected Product(s):
BIG-IP AFM(all modules)

Known Affected Versions:
15.1.0, 15.1.0.1, 15.1.0.2, 15.1.0.3, 15.1.0.4, 15.1.0.5, 15.1.1, 15.1.2, 15.1.2.1, 15.1.3, 15.1.3.1, 15.1.4, 15.1.4.1, 15.1.5, 15.1.5.1, 15.1.6, 15.1.6.1, 15.1.7, 15.1.8, 15.1.8.1, 15.1.8.2, 15.1.9, 15.1.9.1, 15.1.10, 15.1.10.2, 15.1.10.3, 15.1.10.4, 15.1.10.5, 15.1.10.6, 16.1.0, 16.1.1, 16.1.2, 16.1.2.1, 16.1.2.2, 16.1.3, 16.1.3.1, 16.1.3.2, 16.1.3.3, 16.1.3.4, 16.1.3.5, 16.1.4, 16.1.4.1, 16.1.4.2, 16.1.4.3, 16.1.5, 16.1.5.1, 16.1.5.2, 17.1.0, 17.1.0.1, 17.1.0.2, 17.1.0.3, 17.1.1, 17.1.1.1, 17.1.1.2, 17.1.1.3, 17.1.1.4, 17.1.2, 17.1.2.1, 17.5.0

Opened: Oct 08, 2024

Severity: 2-Critical

Symptoms

Modifying DOS timestamp Cookies impacts existing TCP connections with TCP timestamps enabled.

Impact

Segments are lost for existing connections, this might lead to connection closure.

Conditions

- Existing TCP connection with TCP timestamps enabled. - TCP ACK (TS) DOS vector 'Timestamp Cookie' option is modified. (v17.1 or later) - TCP BADACK Flood DOS vector 'Timestamp Cookie VLAN' option is modified. (v15.1, v16.1)

Workaround

None

Fix Information

None

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips