The dissect_pw_eth_heuristic function in epan/dissectors/packet-pw-eth.c in Wireshark 1.6.x before 1.6.13 and 1.8.x before 1.8.5 does not properly handle apparent Ethernet address values at the beginning of MPLS data, which allows remote attackers to cause a denial of service (loop) via a malformed packet.
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A16205
https://bugs.wireshark.org/bugzilla/show_bug.cgi?id=8043
http://www.wireshark.org/security/wnpa-sec-2013-01.html
http://lists.opensuse.org/opensuse-updates/2013-02/msg00037.html
http://lists.opensuse.org/opensuse-updates/2013-02/msg00028.html
http://anonsvn.wireshark.org/viewvc?view=revision&revision=46420