Unspecified vulnerability in packet.c in the GSM A RR dissector in Wireshark 1.2.0 and 1.2.1 allows remote attackers to cause a denial of service (application crash) via unknown vectors related to "an uninitialized dissector handle," which triggers an assertion failure.
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A5423
https://bugs.wireshark.org/bugzilla/show_bug.cgi?id=3893
http://www.wireshark.org/security/wnpa-sec-2009-06.html
http://www.wireshark.org/docs/relnotes/wireshark-1.2.2.html