1.126.1. RHSA-2011:0843: Moderate postfix security update
Updated postfix packages that fix one security issue are now available for Red Hat Enterprise Linux 4, 5, and 6.
The Red Hat Security Response Team has rated this update as having moderate security impact. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available from the CVE link in the References section.
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.