Bug ID 551849: If 1 tmm gets more than 1 Mpps then the 1m stats in dos_stats can be wrong

Last Modified: Nov 07, 2022

Bug Tracker

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

Known Affected Versions:
11.5.1, 11.5.1 HF1, 11.5.1 HF10, 11.5.1 HF11, 11.5.1 HF2, 11.5.1 HF3, 11.5.1 HF4, 11.5.1 HF5, 11.5.1 HF6, 11.5.1 HF7, 11.5.1 HF8, 11.5.1 HF9, 11.5.10, 11.5.2, 11.5.2 HF1, 11.5.3, 11.5.3 HF1, 11.5.3 HF2, 11.5.4, 11.5.4 HF1, 11.5.4 HF2, 11.5.4 HF3, 11.5.4 HF4, 11.5.5, 11.5.6, 11.5.7, 11.5.8, 11.5.9, 11.6.0, 11.6.0 HF1, 11.6.0 HF2, 11.6.0 HF3, 11.6.0 HF4, 11.6.0 HF5, 11.6.0 HF6, 11.6.0 HF7, 11.6.0 HF8, 11.6.1, 11.6.1 HF1, 11.6.1 HF2, 11.6.2, 11.6.2 HF1, 11.6.3, 11.6.3.1, 11.6.3.2, 11.6.3.3, 11.6.3.4, 11.6.4, 11.6.5, 11.6.5.1, 11.6.5.2, 11.6.5.3, 12.0.0, 12.0.0 HF1, 12.0.0 HF2

Fixed In:
12.1.0, 12.0.0 HF3

Opened: Oct 09, 2015
Severity: 3-Major

Symptoms

If 1 tmm with AFM DoS gets more than 1 Mpps then in the dos_stats, where stats_1m is calculated (previous 60s average pps) can be wrong. This can cause the DoS attack to be detected sooner than it should.

Impact

The state will be wrong and AFM could detect a DoS attack before it actually reaches the configured threshold.

Conditions

AFM DoS configured and provisioned. Any 1 tmm gets more than 1 Mpps of a certain kind for which we've configured DoS attack detection - and this could cause the 1 minute average stats to be wrong.

Workaround

None.

Fix Information

Fix the logic which causes the numbers to wrap around.

Behavior Change