Off-by-one error in the is_rtsp_request_or_reply function in epan/dissectors/packet-rtsp.c in the RTSP dissector in Wireshark 1.10.x before 1.10.10 and 1.12.x before 1.12.1 allows remote attackers to cause a denial of service (application crash) via a crafted packet that triggers parsing of a token located one position beyond the current position.