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.
The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.