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4.172. samba
Updated samba packages that fix multiple security issues are now available for Red Hat Enterprise Linux 4 and 5.
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 associated with each description below.
Samba is a suite of programs used by machines to share files, printers, and other information.
Security Fixes
- CVE-2011-2694
- 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-2011-2522
- 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-2010-0787
- A race condition flaw was found in the way the mount.cifs tool mounted CIFS (Common Internet File System) shares. If mount.cifs had the setuid bit set, a local attacker could conduct a symbolic link attack to trick mount.cifs into mounting a share over an arbitrary directory they were otherwise not allowed to mount to, possibly allowing them to escalate their privileges.
- CVE-2010-0547
- It was found that the mount.cifs tool did not properly handle share or directory names containing a newline character. If mount.cifs had the setuid bit set, a local attacker could corrupt the mtab (mounted file systems table) file via a specially-crafted CIFS share mount request.
- CVE-2011-1678
- 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.
Note
mount.cifs from the samba packages 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; the Debian Security Team for reporting CVE-2010-0787; 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; Yoshihiro Ishikawa of LAC Co., Ltd. as the original reporter of CVE-2011-2522; and the Debian Security Team acknowledges Ronald Volgers as the original reporter of CVE-2010-0787.
Users of Samba 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.
Updated samba packages that fix one security issue, one bug, and add one enhancement are now available for Red Hat Enterprise Linux 5.
The Red Hat Security Response Team has rated this update as having low security impact. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available from the CVE link associated with the description below.
Samba is an open-source implementation of the Server Message Block (SMB) or Common Internet File System (CIFS) protocol, which allows PC-compatible machines to share files, printers, and other information.
Security Fix
- CVE-2010-0926
- The default Samba server configuration enabled both the "wide links" and "unix extensions" options, allowing Samba clients with write access to a share to create symbolic links that point to any location on the file system. Clients connecting with CIFS UNIX extensions disabled could have such links resolved on the server, allowing them to access and possibly overwrite files outside of the share. With this update, "wide links" is set to "no" by default. In addition, the update ensures "wide links" is disabled for shares that have "unix extensions" enabled.
Warning
This update may cause files and directories that are only linked to Samba shares using symbolic links to become inaccessible to Samba clients. In deployments where support for CIFS UNIX extensions is not needed (such as when files are exported to Microsoft Windows clients), administrators may prefer to set the "unix extensions" option to "no" to allow the use of symbolic links to access files out of the shared directories. All existing symbolic links in a share should be reviewed before re-enabling "wide links".
Bug Fix
- BZ#768908
- The smbclient tool sometimes failed to return the proper exit status code. Consequently, using smbclient in a script caused some scripts to fail. With this update, an upstream patch has been applied and smbclient now returns the correct exit status.
Enhacement
- BZ#736124
- With this update, support for Windows Server 2008 R2 domains has been added.
Users are advised to upgrade to these updated samba packages, which correct these issues and add this enhancement. After installing this update, the smb service will be restarted automatically.
