Pidgin is an instant messaging program which can log in to multipleaccounts on multiple instant messaging networks simultaneously.An input sanitization flaw was found in the way the AOL Open System forCommunication in Realtime (OSCAR) protocol plug-in in Pidgin, used by theAOL ICQ and AIM instant messaging systems, escaped certain UTF-8characters. A remote attacker could use this flaw to crash Pidgin via aspecially-crafted OSCAR message. (CVE-2011-4601)An input sanitization flaw was found in the way the Pidgin SILC (SecureInternet Live Conferencing) protocol plug-in escaped certain UTF-8characters in channel messages. A remote attacker could use this flaw tocrash Pidgin via a specially-crafted SILC message. (CVE-2011-4603)Multiple NULL pointer dereference flaws were found in the Jingle extensionof the Extensible Messaging and Presence Protocol (XMPP) protocol plug-inin Pidgin. A remote attacker could use these flaws to crash Pidgin via aspecially-crafted Jingle multimedia message. (CVE-2011-4602)Red Hat would like to thank the Pidgin project for reporting these issues.Upstream acknowledges Evgeny Boger as the original reporter ofCVE-2011-4601; Diego Bauche Madero from IOActive as the original reporterof CVE-2011-4603; and Thijs Alkemade as the original reporter ofCVE-2011-4602.All Pidgin users should upgrade to these updated packages, which containbackported patches to resolve these issues. Pidgin must be restarted forthis update to take effect.