In Wireshark 2.4.0, the Modbus dissector could crash with a NULL pointer dereference. This was addressed in epan/dissectors/packet-mbtcp.c by adding length validation.Referenceshttps://code.wireshark.org/review/gitweb?p=wireshark.git%3Ba=commit%3Bh=b87ffbd12bddf64582c0a6e082b462744474de94http://www.securityfocus.com/bid/100545https://bugs.wireshark.org/bugzilla/show_bug.cgi?id=13925https://www.wireshark.org/security/wnpa-sec-2017-40.htmlhttp://www.securitytracker.com/id/1039254
