A Security Vulnerability in OpenSolaris smbfs(7FS) may Expose Data to Unauthorized Users

---

A security vulnerability in OpenSolaris smbfs(7FS) may expose data to unauthorized users:

1. Impact

Information disclosure security vulnerability in OpenSolaris smbfs(7FS) when using default mount permissions may allow a local unprivileged user unauthorized access to read contents of the files and list directories on a CIFS (Common Internet File System) mounted volume.

2. Contributing Factors

This issue can occur in the following releases:

SPARC Platform

• OpenSolaris based upon builds snv_84 through snv_110

x86 Platform

• OpenSolaris based upon builds snv_84 through snv_110

Note 1: Solaris 8, 9 and 10 are not impacted by this issue.

Note 2: OpenSolaris distributions may include additional bug fixes above and beyond the build from which it was derived.  To determine the base build of OpenSolaris, the following command can be used:

    $ uname -v
    snv_86

Note 3: This issue only affects systems which are setup to allow mouting of CIFS shares. This can be determined by checking the status of the "svc:/network/smb/client" service using a command such as the following:

    $ svcs svc:/network/smb/client:default
    STATE          STIME    FMRI
    disabled       14:22:02 svc:/network/smb/client:default

To determine if a mounted CIFS volume is vulnerable, first locate the mount point of any CIFS volumes on the host using a command such as the following:

    # mount -v | grep smbfs
    //server/share on /mnt type smbfs 
    remote/read/write/setuid/devices/intr/noxattr/dev=6480002 on Wed Jun 10 11:42:10 2009

and then check the permissions of all the directories and files located on the mounted volume by using the "ls" command similar to the following:

    # ls -ld /mnt
    drwxr-xr-x   1 root     root       16384 Apr  9 18:20 /mnt

The output from the above command will indicate which users and groups have permission to access the contents of the examined directory.

3. Symptoms

There are no predictable symptoms that would indicate the described vulnerability has been exploited.

4. Workaround

To work around the described issue, first unmount the affected share, and remount it with options to set the permissions of the CIFS mount point to 700 by using the following command:

    # mount -F smbfs -o dirperms=700,fileperms=600 ...

5. Resolution

This issue is addressed in the following releases:

SPARC Platform

• OpenSolaris based upon builds snv_111 or later
  

x86 Platform

• OpenSolaris based upon builds snv_111 or later

For more information on Security Sun Alerts, see Technical Instruction ID 213557.

This Sun Alert notification is being provided to you on an "AS IS" basis. This Sun Alert notification may contain information provided by third parties. The issues described in this Sun Alert notification may or may not impact your system(s). Sun makes no representations, warranties, or guarantees as to the information contained herein. ANY AND ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT, ARE HEREBY DISCLAIMED. BY ACCESSING THIS DOCUMENT YOU ACKNOWLEDGE THAT SUN SHALL IN NO EVENT BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, PUNITIVE, OR CONSEQUENTIAL DAMAGES THAT ARISE OUT OF YOUR USE OR FAILURE TO USE THE INFORMATION CONTAINED HEREIN. This Sun Alert notification contains Sun proprietary and confidential information. It is being provided to you pursuant to the provisions of your agreement to purchase services from Sun, or, if you do not have such an agreement, the Sun.com Terms of Use. This Sun Alert notification may only be used for the purposes contemplated by these agreements.

Copyright 2000-2009 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, CA 95054 U.S.A. All rights reserved.




Attachments

This solution has no attachment