On F5 BIG-IP versions 13.0.0 or 12.1.0 - 12.1.3.1, when a specifically configured virtual server receives traffic of an undisclosed nature, TMM will crash and take the configured failover action, potentially causing a denial of service. The configuration which exposes this issue is not common and in general does not work when enabled in previous versions of BIG-IP. Starting in 12.1.0, BIG-IP will crash if the configuration which exposes this issue is enabled and the virtual server receives non TCP traffic. With the fix of this issue, additional configuration validation logic has been added to prevent this configuration from being applied to a virtual server. There is only data plane exposure to this issue with a non-standard configuration. There is no control plane exposure.