6.8 - RHSA-2008:0297

Problem Description:

An updated dovecot package that fixes several security issues and various bugs is now available for Red Hat Enterprise Linux 5.

This update has been rated as having low security impact by the Red Hat Security Response Team.

2. Relevant releases/architectures:

RHEL Desktop Workstation (v. 5 client) - i386, x86_64 Red Hat Enterprise Linux (v. 5 server) - i386, ia64, ppc, s390x, x86_64

3. Description:

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

A flaw was discovered in the way Dovecot handled the "mail_extra_groups" option. An authenticated attacker with local shell access could leverage this flaw to read, modify, or delete other users mail that is stored on the mail server. (CVE-2008-1199)

This issue did not affect the default Red Hat Enterprise Linux 5 Dovecot configuration. This update adds two new configuration options -- "mail_privileged_group" and "mail_access_groups" -- to minimize the usage of additional privileges.

A directory traversal flaw was discovered in Dovecot's zlib plug-in. An authenticated user could use this flaw to view other compressed mailboxes with the permissions of the Dovecot process. (CVE-2007-2231)

A flaw was found in the Dovecot ACL plug-in. User with only insert permissions for a mailbox could use the "COPY" and "APPEND" commands to set additional message flags. (CVE-2007-4211)

A flaw was found in a way Dovecot cached LDAP query results in certain configurations. This could possibly allow authenticated users to log in as a different user who has the same password. (CVE-2007-6598)

As well, this updated package fixes the following bugs:

* configuring "userdb" and "passdb" to use LDAP caused Dovecot to hang. A segmentation fault may have occurred. In this updated package, using an LDAP backend for "userdb" and "passdb" no longer causes Dovecot to hang.

* the Dovecot "login_process_size" limit was configured for 32-bit systems. On 64-bit systems, when Dovecot was configured to use either IMAP or POP3, the log in processes crashed with out-of-memory errors. Errors such as the following were logged:

pop3-login: pop3-login: error while loading shared libraries: libsepol.so.1: failed to map segment from shared object: Cannot allocate memory

In this updated package, the "login_process_size" limit is correctly configured on 64-bit systems, which resolves this issue.

Note: this updated package upgrades dovecot to version 1.0.7. For further details, refer to the Dovecot changelog: http://koji.fedoraproject.org/koji/buildinfo?buildID=23397

Users of dovecot are advised to upgrade to this updated package, which resolves these issues.

4. Solution:

Before applying this update, make sure that all previously-released errata relevant to your system have been applied.

This update is available via Red Hat Network. Details on how to use the Red Hat Network to apply this update are available at http://kbase.redhat.com/faq/FAQ_58_10188

5. Bugs fixed (http://bugzilla.redhat.com/):

238439 - CVE-2007-2231 Directory traversal in dovecot with zlib plugin 245249 - Dovecot hangs while using ldap backend. 251007 - CVE-2007-4211 Dovecot possible privilege ascalation in ACL plugin 253363 - Dovecot pop3-login/imap-login crash with OOM error 331441 - Please consider upgrading Dovecot to 1.0rc23 at least 380401 - tracker bug for 1.0.7 rebase 427575 - CVE-2007-6598: dovecot LDAP+auth cache user login mixup 436927 - CVE-2008-1199 dovecot: insecure mail_extra_groups option