The dissect_per_length_determinant function in epan/dissectors/packet-per.c in the ASN.1 PER dissector in Wireshark 1.8.x before 1.8.9 and 1.10.x before 1.10.1 does not initialize a length field in certain abnormal situations, which allows remote attackers to cause a denial of service (application crash) via a crafted packet.