Pidgin is an instant messaging program which can log in to multiple accounts on multiple instant messaging networks simultaneously. Multiple NULL pointer dereference flaws were found in the way the Pidgin Yahoo! Messenger Protocol plug-in handled malformed YMSG packets. A remote attacker could use these flaws to crash Pidgin via a specially-crafted notification message. Red Hat would like to thank the Pidgin project for reporting these issues. Upstream acknowledges Marius Wachtler as the original reporter. This update also fixes the following bugs: * Previous versions of the pidgin package did not properly clear certain data structures used in libpurple/cipher.c when attempting to free them. Partial information could potentially be extracted from the incorrectly cleared regions of the previously freed memory. With this update, data structures are properly cleared when freed. * This erratum upgrades Pidgin to upstream version 2.7.9. Users of pidgin should upgrade to these updated packages, which resolve these issues. Pidgin must be restarted for this update to take effect.