plugins/ethercat/packet-ecatmb.c in the EtherCAT Mailbox dissector in Wireshark 1.4.x before 1.4.15, 1.6.x before 1.6.10, and 1.8.x before 1.8.2 does not properly handle certain integer fields, which allows remote attackers to cause a denial of service (application exit) via a malformed packet.