Bug ID 570905: Some Internet Explorer Browsers challenged with CAPTCHA when "Proactive Bot Defense" is enabled

Last Modified: Oct 06, 2020

Bug Tracker

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

Known Affected Versions:
12.0.0, 12.0.0 HF1, 12.0.0 HF2, 12.0.0 HF3, 12.0.0 HF4

Opened: Jan 30, 2016
Severity: 3-Major

Symptoms

Some rare cases of Internet Explorer browsers that are running on Windows Server and connected via Remote Desktop may receive a CAPTCHA challenge instead of passing through directly, when "Proactive Bot Defense" is enabled on the DoS profile, and "Block requests from suspicious browsers" is also enabled.

Impact

Some rare cases of Internet Explorer browsers that are running on Windows Server and connected via Remote Desktop may receive a CAPTCHA challenge instead of passing through directly.

Conditions

"Proactive Bot Defense" is enabled on the DoS profile, and "Block requests from suspicious browsers" is also enabled.

Workaround

Disabling the "Block requests from suspicious browsers" check-box on the DoS profile will prevent this problem.

Fix Information

None

Behavior Change