Bug ID 1094145: AFM does not detect NXDOMAIN attack when DNS cache is activated.

Last Modified: Nov 07, 2022

Bug Tracker

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

Known Affected Versions:
15.1.0, 15.1.0.1, 15.1.0.2, 15.1.0.3, 15.1.0.4, 15.1.0.5, 15.1.1, 15.1.2, 15.1.2.1, 15.1.3, 15.1.3.1, 15.1.4, 15.1.4.1, 15.1.5, 15.1.5.1, 15.1.6, 15.1.6.1, 15.1.7, 15.1.8

Opened: Apr 05, 2022
Severity: 4-Minor

Symptoms

When the DNS cache is activated, the NXDOMAIN DoS vector does not increase for the virtual server context. As a result, NXDOMAIN flood attack is never detected/mitigated at the virtual server context. At the device level, NXDOMAIN stats are incorrect.

Impact

NXDOMAIN flood attack is not detected/mitigated at the virtual server context.

Conditions

-- DNS cache is activated -- An NXDOMAIN DoS vector occurs

Workaround

None

Fix Information

None

Behavior Change