Bug ID 961509: ASM blocks WebSocket frames with signature matched but Transparent policy

Last Modified: May 29, 2024

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

Known Affected Versions:
14.1.2, 14.1.2.1, 14.1.2.2, 14.1.2.3, 14.1.2.4, 14.1.2.5, 14.1.2.6, 14.1.2.7, 14.1.2.8, 14.1.3, 14.1.3.1, 14.1.4, 14.1.4.1, 14.1.4.2, 14.1.4.3, 14.1.4.4, 14.1.4.5, 15.0.0, 15.0.1, 15.0.1.1, 15.0.1.2, 15.0.1.3, 15.0.1.4, 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, 16.0.0, 16.0.0.1, 16.0.1, 16.0.1.1, 16.0.1.2

Fixed In:
17.0.0, 16.1.2.2, 15.1.5.1, 14.1.4.6

Opened: Nov 01, 2020

Severity: 3-Major

Symptoms

WebSocket frames receive a close frame

Impact

WebSocket frame blocked in transparent mode

Conditions

-- ASM provisioned -- ASM policy attached to a virtual server -- WebSocket profile attached to a virtual server -- ASM policy transparent mode enabled

Workaround

Change signatures blocking settings to Learn = Yes, Alarm = Yes, Block = No

Fix Information

WebSocket frame blocking condition now takes into account global transparent mode setting.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips