Cisco IOS Unified Border Element (CUBE) in Cisco IOS before 15.3(2)T allows remote authenticated users to cause a denial of service (input queue wedge) via a crafted series of RTCP packets, aka Bug ID CSCuc42518.
Improper Input Validation The product receives input or data, but it does
not validate or incorrectly validates that the input has the
properties that are required to process the data safely and
correctly.