A NULL pointer dereference flaw was found in GStreamer's RTSP support library. The vulnerability occurs while parsing an Authorization or WWW-Authenticate header that uses Digest authentication. Specially crafted whitespace placement around a parameter's terminator can cause an internal length calculation to underflow, leading to a crash of the process parsing the header. On an RTSP server this can be triggered by a remote, unauthenticated attacker sending a single malformed request when the server has authentication enabled; the same flaw can also be triggered against an RTSP client by a malicious or compromised RTSP server. Successful exploitation results in a denial of service (application crash) and has no confirmed impact on confidentiality or integrity.