Bug ID 745140: Legitimate user might get blocked or get CAPTCHA by "bot defense"

Last Modified: Dec 17, 2025

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

Known Affected Versions:
14.1.0, 14.1.0.1, 14.1.0.2, 14.1.0.3, 14.1.0.5, 14.1.0.6, 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, 14.1.4.6, 14.1.5, 14.1.5.1, 14.1.5.2, 14.1.5.3, 14.1.5.4, 14.1.5.6, 15.0.0, 15.0.1, 15.0.1.1, 15.0.1.2, 15.0.1.3, 15.0.1.4, 17.1.0, 17.1.0.1, 17.1.0.2, 17.1.0.3, 17.1.1, 17.1.1.1, 17.1.1.2, 17.1.1.3, 17.1.1.4, 17.1.2, 17.1.2.1, 17.1.2.2, 17.1.3, 17.5.0, 17.5.1, 17.5.1.2, 17.5.1.3

Opened: Sep 25, 2018

Severity: 3-Major

Symptoms

Client user gets blocked or sees a CAPTCHA when clicking the mouse button

Impact

Client user gets blocked or get CAPTCHA

Conditions

Bot defense profile is configured with "Rapid Mouse Click" anomaly set to "Block" or "CAPTCHA"

Workaround

Disable "Rapid Mouse Click" anomaly in the bot-defense profile: 1. Navigate to Security ›› Bot Defense, then select the relevant Bot Profile. 2. From the left-hand menu, click Bot Mitigation Settings. 3. In the Mitigation Settings Exceptions section, click Add Exception. 4. In the search pop-up, search for Rapid Mouse Clicks and add it to the exception list. 5. Update the mitigation action from Block to None.

Fix Information

None

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips