The dissect_r3_upstreamcommand_queryconfig function in epan/dissectors/packet-assa_r3.c in the Assa Abloy R3 dissector in Wireshark 1.8.x before 1.8.8 does not properly handle a zero-length item, which allows remote attackers to cause a denial of service (infinite loop, and CPU and memory consumption) via a crafted packet.
The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.