6.8 - RHSA-2011:1221

Problem Description:

Updated samba and cifs-utils packages that fix multiple security issues and one bug are now available for Red Hat Enterprise Linux 6.

The Red Hat Security Response Team has rated this update as having moderate security impact. Common Vulnerability Scoring System (CVSS) base scores, which give detailed severity ratings, are available for each vulnerability from the CVE links in the References section.

2. Relevant releases/architectures:

Red Hat Enterprise Linux Desktop (v. 6) - i386, x86_64 Red Hat Enterprise Linux Desktop Optional (v. 6) - i386, x86_64 Red Hat Enterprise Linux HPC Node (v. 6) - x86_64 Red Hat Enterprise Linux HPC Node Optional (v. 6) - x86_64 Red Hat Enterprise Linux Server (v. 6) - i386, ppc64, s390x, x86_64 Red Hat Enterprise Linux Server Optional (v. 6) - i386, ppc64, s390x, x86_64 Red Hat Enterprise Linux Workstation (v. 6) - i386, x86_64 Red Hat Enterprise Linux Workstation Optional (v. 6) - i386, x86_64

3. Description:

Samba is a suite of programs used by machines to share files, printers, and other information. The cifs-utils package contains utilities for mounting and managing CIFS (Common Internet File System) shares.

A cross-site scripting (XSS) flaw was found in the password change page of the Samba Web Administration Tool (SWAT). If a remote attacker could trick a user, who was logged into the SWAT interface, into visiting a specially-crafted URL, it would lead to arbitrary web script execution in the context of the user's SWAT session. (CVE-2011-2694)

It was found that SWAT web pages did not protect against Cross-Site Request Forgery (CSRF) attacks. If a remote attacker could trick a user, who was logged into the SWAT interface, into visiting a specially-crafted URL, the attacker could perform Samba configuration changes with the privileges of the logged in user. (CVE-2011-2522)

It was found that the fix for CVE-2010-0547, provided in the cifs-utils package included in the GA release of Red Hat Enterprise Linux 6, was incomplete. The mount.cifs tool did not properly handle share or directory names containing a newline character, allowing a local attacker to corrupt the mtab (mounted file systems table) file via a specially-crafted CIFS share mount request, if mount.cifs had the setuid bit set. (CVE-2011-2724)

It was found that the mount.cifs tool did not handle certain errors correctly when updating the mtab file. If mount.cifs had the setuid bit set, a local attacker could corrupt the mtab file by setting a small file size limit before running mount.cifs. (CVE-2011-1678)

Note: mount.cifs from the cifs-utils package distributed by Red Hat does not have the setuid bit set. We recommend that administrators do not manually set the setuid bit for mount.cifs.

Red Hat would like to thank the Samba project for reporting CVE-2011-2694 and CVE-2011-2522, and Dan Rosenberg for reporting CVE-2011-1678. Upstream acknowledges Nobuhiro Tsuji of NTT DATA Security Corporation as the original reporter of CVE-2011-2694, and Yoshihiro Ishikawa of LAC Co., Ltd. as the original reporter of CVE-2011-2522.

This update also fixes the following bug:

* If plain text passwords were used ("encrypt passwords = no" in "/etc/samba/smb.conf"), Samba clients running the Windows XP or Windows Server 2003 operating system may not have been able to access Samba shares after installing the Microsoft Security Bulletin MS11-043. This update corrects this issue, allowing such clients to use plain text passwords to access Samba shares. (BZ#728517)

Users of samba and cifs-utils are advised to upgrade to these updated packages, which contain backported patches to resolve these issues. After installing this update, the smb service will be restarted automatically.

4. Solution:

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

This update is available via the Red Hat Network. Details on how to use the Red Hat Network to apply this update are available at https://access.redhat.com/kb/docs/DOC-11259

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

695925 - CVE-2011-1678 samba/cifs-utils: mount.cifs and umount.cifs fail to anticipate RLIMIT_FSIZE 721348 - CVE-2011-2522 samba (SWAT): Absent CSRF protection in various Samba web configuration formulars 722537 - CVE-2011-2694 samba (SWAT): XSS flaw in Change Password page 726691 - CVE-2011-2724 samba, cifs-utils: mount.cifs incorrect fix for CVE-2010-0547 728517 - Windows security patch KB2536276 prevents access to samba shares