The tNetTaskLimit process on the Transport Node Controller (TNC) on Cisco ONS 15454 devices with software 9.6 and earlier does not properly prioritize health pings, which allows remote attackers to cause a denial of service (watchdog timeout and TNC reset) via a flood of network traffic, aka Bug ID CSCud97155.

Cisco IOS 11.x and 12.0 through 12.2 allows remote attackers to cause a denial of service (traffic block) by sending a particular sequence of IPv4 packets to an interface on the device, causing the input queue on that interface to be marked as full.