Bug ID 1957977: Auto-learned DoS Vector attack is detected even with low rate of traffic on HA Pair during Failover

Last Modified: Jun 19, 2025

Affected Product(s):
BIG-IP AFM, Install/Upgrade(all modules)

Known Affected Versions:
17.1.2.1, 17.1.2.2

Opened: May 22, 2025

Severity: 3-Major

Symptoms

After upgrading BIG-IP AFM from 15.1.8 to 17.1.2, DoS vectors (especially "Non TCP connection") are triggered and start attack detected, even though there is no actual attack or stress (CPU usage is low). The detection threshold is set to 0, causing false positives.

Impact

Logs show attack detection with thresholds at 0, despite no actual stress or attack. This leads to immediate and incorrect attack detection, causing false alarm even when there is no actual attack or system stress.

Conditions

-- Upgrade from 15.1.8 to 17.1.2 (with EHF/instrumented TMM). -- Device becomes Active after upgrade/failover. -- AFM Device DoS vectors in Fully Auto mode.

Workaround

None

Fix Information

None

Behavior Change

Guides & references

K10134038: F5 Bug Tracker Filter Names and Tips