(RHSA-2011:0600) Moderate: dovecot security and enhancement update

Dovecot is an IMAP server for Linux, UNIX, and similar operating systems,
primarily written with security in mind.

A flaw was found in the way Dovecot handled SIGCHLD signals. If a large
amount of IMAP or POP3 session disconnects caused the Dovecot master
process to receive these signals rapidly, it could cause the master process
to crash. (CVE-2010-3780)

A flaw was found in the way Dovecot processed multiple Access Control Lists
(ACL) defined for a mailbox. In some cases, Dovecot could fail to apply the
more specific ACL entry, possibly resulting in more access being granted to
the user than intended. (CVE-2010-3707)

This update also adds the following enhancement:

• This erratum upgrades Dovecot to upstream version 2.0.9, providing
  multiple fixes for the “dsync” utility and improving overall performance.
  Refer to the “/usr/share/doc/dovecot-2.0.9/ChangeLog” file after installing
  this update for further information about the changes. (BZ#637056)

Users of dovecot are advised to upgrade to these updated packages, which
resolve these issues and add this enhancement. After installing the updated
packages, the dovecot service will be restarted automatically.