(RHSA-2011:1508) Moderate: cyrus-imapd security update

The cyrus-imapd packages contain a high-performance mail server with IMAP,
POP3, NNTP, and Sieve support.

An authentication bypass flaw was found in the cyrus-imapd NNTP server,
nntpd. A remote user able to use the nntpd service could use this flaw to
read or post newsgroup messages on an NNTP server configured to require
user authentication, without providing valid authentication credentials.
(CVE-2011-3372)

A NULL pointer dereference flaw was found in the cyrus-imapd IMAP server,
imapd. A remote attacker could send a specially-crafted mail message to a
victim that would possibly prevent them from accessing their mail normally,
if they were using an IMAP client that relies on the server threading IMAP
feature. (CVE-2011-3481)

Red Hat would like to thank the Cyrus IMAP project for reporting the
CVE-2011-3372 issue. Upstream acknowledges Stefan Cornelius of Secunia
Research as the original reporter of CVE-2011-3372.

Users of cyrus-imapd are advised to upgrade to these updated packages,
which contain backported patches to correct these issues. After installing
the update, cyrus-imapd will be restarted automatically.