A denial-of-service vulnerability exists in the Pixar Renderman IT Display Service 21.6 (0x67). The vulnerability is present in the parsing of a network packet without proper validation of the packet. The data read by the application is not validated, and its use can lead to a null pointer dereference. The IT application is opened by a user and then listens for a connection on port 4001. An attacker can deliver an attack once the application has been opened.