(RHSA-2011:0843) Moderate: postfix security update

Postfix is a Mail Transport Agent (MTA), supporting LDAP, SMTP AUTH (SASL),
and TLS.

A heap-based buffer over-read flaw was found in the way Postfix performed
SASL handlers management for SMTP sessions, when Cyrus SASL authentication
was enabled. A remote attacker could use this flaw to cause the Postfix
smtpd server to crash via a specially-crafted SASL authentication request.
The smtpd process was automatically restarted by the postfix master process
after the time configured with service_throttle_time elapsed.
(CVE-2011-1720)

Note: Cyrus SASL authentication for Postfix is not enabled by default.

Red Hat would like to thank the CERT/CC for reporting this issue. Upstream
acknowledges Thomas Jarosch of Intra2net AG as the original reporter.

Users of Postfix are advised to upgrade to these updated packages, which
contain a backported patch to resolve this issue. After installing this
update, the postfix service will be restarted automatically.