RHSA-2008:0297 - Security Advisory

Topic

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.

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.

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

Affected Products

• Red Hat Enterprise Linux Server 5 x86_64
• Red Hat Enterprise Linux Server 5 ia64
• Red Hat Enterprise Linux Server 5 i386
• Red Hat Enterprise Linux Workstation 5 x86_64
• Red Hat Enterprise Linux Workstation 5 i386
• Red Hat Enterprise Linux for IBM z Systems 5 s390x
• Red Hat Enterprise Linux for Power, big endian 5 ppc
• Red Hat Enterprise Linux Server from RHUI 5 x86_64
• Red Hat Enterprise Linux Server from RHUI 5 i386

Fixes

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

CVEs

• CVE-2007-2231
• CVE-2007-6598
• CVE-2007-4211
• CVE-2008-1199

References

• http://www.redhat.com/security/updates/classification/#low