The pidgin_conv_chat_rename_user function in gtkconv.c in Pidgin before 2.10.2 allows remote attackers to cause a denial of service (NULL pointer dereference and application crash) by changing a nickname while in an XMPP chat room.
developer.pidgin.im/ticket/14392
developer.pidgin.im/viewmtn/revision/diff/10ead4688e3af4132d454fa3bc241480500651c9/with/d1d77da56217f3a083e1d459bef054db9f1d5699/pidgin/gtkconv.c
developer.pidgin.im/viewmtn/revision/info/d1d77da56217f3a083e1d459bef054db9f1d5699
pidgin.im/news/security/?id=60
www.mandriva.com/security/advisories?name=MDVSA-2012:029
oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A18406