(RHSA-2011:1221) Moderate: samba and cifs-utils security and bug fix update

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.