msg.c in the MSN protocol plugin in libpurple in Pidgin before 2.10.4 does not properly handle crafted characters, which allows remote servers to cause a denial of service (application crash) by placing these characters in a text/plain message.
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A17448
https://hermes.opensuse.org/messages/15136503
http://www.securityfocus.com/bid/53400
http://www.mandriva.com/security/advisories?name=MDVSA-2012:082
http://secunia.com/advisories/50005