Bug ID 605383: Requsts are dropped when custom captcha response page is longer than 1024 bytes

Last Modified: Sep 13, 2023

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

Known Affected Versions:
12.1.0, 12.1.1, 12.1.2, 12.1.3, 12.1.3.1, 12.1.3.2, 12.1.3.3, 12.1.3.4, 12.1.3.5, 12.1.3.6, 12.1.3.7, 12.1.4, 12.1.4.1, 12.1.5, 12.1.5.1, 12.1.5.2, 12.1.5.3, 12.1.6

Fixed In:
13.0.0

Opened: Jul 18, 2016

Severity: 2-Critical

Symptoms

When configuring custom Captcha response page bigger than 1024 bytes, requests are getting dropped instead of getting Captcha response. There is also no indication of error.

Impact

Site availability decrease.

Conditions

1. During Captcha mitigation in DOSL7 2. Custom Captcha response page 3. Requests are getting dropped instead of getting Captcha response.

Workaround

Change Captcha response to be smaller than 1024 bytes

Fix Information

No limitation for Captcha page.

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips