The msn_emoticon_msg function in slp.c in the MSN protocol plugin in libpurple in Pidgin before 2.7.0 allows remote authenticated users to cause a denial of service (NULL pointer dereference and application crash) via a custom emoticon in a malformed SLP message.
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A18547
https://exchange.xforce.ibmcloud.com/vulnerabilities/58559
https://bugzilla.redhat.com/show_bug.cgi?id=589973
http://www.vupen.com/english/advisories/2010/2755
http://www.vupen.com/english/advisories/2010/1141
http://www.ubuntu.com/usn/USN-1014-1
http://www.redhat.com/support/errata/RHSA-2010-0788.html