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 performedSASL handlers management for SMTP sessions, when Cyrus SASL authenticationwas enabled. A remote attacker could use this flaw to cause the Postfixsmtpd server to crash via a specially-crafted SASL authentication request.The smtpd process was automatically restarted by the postfix master processafter 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. Upstreamacknowledges Thomas Jarosch of Intra2net AG as the original reporter.Users of Postfix are advised to upgrade to these updated packages, whichcontain a backported patch to resolve this issue. After installing thisupdate, the postfix service will be restarted automatically.