A null pointer dereference vulnerability exists in the Distributed Transaction component of Bloomberg Comdb2 8.1 when processing a number of fields used for coordination. A specially crafted protocol buffer message can lead to a denial of service. An attacker can simply connect to a database instance over TCP and send the crafted message to trigger this vulnerability.
A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit.