(RHSA-2010:0970) Critical: exim security update

Exim is a mail transport agent (MTA) developed at the University of
Cambridge for use on Unix systems connected to the Internet.

A buffer overflow flaw was discovered in Exim’s internal
string_vformat() function. A remote attacker could use this flaw to
execute arbitrary code on the mail server running Exim. (CVE-2010-4344)

Note: successful exploitation would allow a remote attacker to execute
arbitrary code as root on a Red Hat Enterprise Linux 4 or 5 system that
is running the Exim mail server. An exploit for this issue is known to
exist.

For additional information regarding this flaw, along with mitigation
advice, please see the Knowledge Base article linked to in the
References section of this advisory.

Users of Exim are advised to update to these erratum packages which
contain a backported patch to correct this issue. After installing this
update, the Exim daemon will be restarted automatically.