The cyrus-imapd packages contain a high-performance mail server with IMAP, POP3, NNTP, and Sieve support.A buffer overflow flaw was found in the cyrus-imapd NNTP server, nntpd. A remote user able to use the nntpd service could use this flaw to crash the nntpd child process or, possibly, execute arbitrary code with the privileges of the cyrus user. Users of cyrus-imapd are advised to upgrade to these updated packages, which contain a backported patch to correct this issue. After installing the update, cyrus-imapd will be restarted automatically.