Bug ID 761565: ASM BD core when custom captcha page configured size more than 45K with %ASM.captcha.support_id% placeholder is at the end

Last Modified: Apr 10, 2019

Bug Tracker

Affected Product:  See more info
BIG-IP ASM(all modules)

Known Affected Versions:
13.1.0,,,,,,,,, 13.1.1,,,,, 14.0.0,,,,, 14.1.0,,,

Opened: Mar 18, 2019
Severity: 2-Critical


ASM BD crash when custom captcha page configured size is 45K


There is an ASM BD crash that occurs upon a request protection by CAPTCHA mitigation. If configured for high availability (HA), failover occurs.


- ASM provisioned. - ASM policy attached to a virtual server. - CAPTCHA page size is bigger than 45 KB. - CAPTCHA protection is enabled via brute force or ASM::captcha iRule.


Define CAPTCHA page sizes smaller than 45 KB.

Fix Information


Behavior Change