The jabber:iq:auth implementation in IQAuthHandler.java in Ignite Realtime Openfire before 3.6.4 allows remote authenticated users to change the passwords of arbitrary accounts via a modified username element in a passwd_change action.
http://secunia.com/advisories/34976
http://www.igniterealtime.org/builds/openfire/docs/latest/changelog.html
http://www.igniterealtime.org/community/message/190280
http://www.igniterealtime.org/issues/browse/JM-1531
http://www.securityfocus.com/bid/34804