The dissect_r3_cmd_alarmconfigure function in epan/dissectors/packet-assa_r3.c in the R3 dissector in Wireshark 1.6.x before 1.6.13 and 1.8.x before 1.8.5 does not properly handle a certain alarm length, which allows remote attackers to cause a denial of service (infinite loop) via a malformed packet.