Bug ID 670516: Illegal metachar in headers violation may happen on legitimate traffic

Last Modified: Jul 12, 2023

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

Known Affected Versions:
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

Opened: Jun 22, 2017

Severity: 3-Major

Symptoms

False positive 'Illegal meta character in header' violation is posted.

Impact

ASM violation. Blocking page.

Conditions

This occurs when the browser sends un-escaped headers in a specific language.

Workaround

To work around this issue, turn off the 'Illegal meta character in header' violation. Note: This is a known issue with Microsoft Internet Explorer v11.

Fix Information

None

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips