AusCERT - ESB-2007.1017 -- [Solaris] -- Solaris 10 Kernel Patches May Allow Privileged Remote Users to Gain Root Access to Files Shared by NFS Servers

HOME
About AusCERT
Membership
PKI Services
Training
Publications
Sec. Bulletins
Conferences
News & Media
Services
Web Log
Site Map
Site Help
Member login
ESB-2007.1017 -- [Solaris] -- Solaris 10 Kernel Patches May Allow Privileged Remote Users to Gain Root Access to Files Shared by NFS Servers
Date: 09 January 2008

Click here for printable version
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

===========================================================================
             AUSCERT External Security Bulletin Redistribution

                        ESB-2007.1017 -- [Solaris]
        Solaris 10 Kernel Patches May Allow Privileged Remote Users
            to Gain Root Access to Files Shared by NFS Servers
                              10 January 2008

===========================================================================

        AusCERT Security Bulletin Summary
        ---------------------------------

Product:              Kernel
Publisher:            Sun Microsystems
Operating System:     Solaris 10
Impact:               Root Compromise
Access:               Existing Account

Original Bulletin:    
  http://sunsolve.sun.com/search/printfriendly.do?assetkey=1-26-103162-1

Revision History:      January 10 2008: Updated the Impact section to 
                                        detail that the vulnerability is 
                                        exploitable by remote clients 
                                        instead of systems which are not 
                                        part of the configured netgroup.
                      December 17 2007: Initial Release

- --------------------------BEGIN INCLUDED TEXT--------------------

Sun(sm) Alert Notification
     * Sun Alert ID: 103162
     * Synopsis: Solaris 10 Kernel Patches May Allow Privileged Remote
       Users to Gain Root Access to Files Shared by NFS Servers
     * Category: Security, Availability
     * Product: Solaris 10 Operating System
     * BugIDs: 6602070
     * Avoidance: Patch, Workaround
     * State: Resolved
     * Date Released: 13-Dec-2007
     * Date Closed: 13-Dec-2007
     * Date Modified: 14-Dec-2007, 21-Dec-2007, 08-Jan-2008

1. Impact

   A security vulnerability exists for Solaris 10 systems with kernel
   patches 120011-04 or later (SPARC) and 120012-04 or later (x86) which
   are configured as NFS servers and grant root user access to remote
   clients. This vulnerability may allow root users on remote clients
   which are not authorized to access the shared file systems as root to
   also have root access to files shared by the NFS server.

2. Contributing Factors

   This issue can occur in the following releases:

   SPARC Platform:
     * Solaris 10 with patch 120011-04 or later and without patch
       127111-05

   x86 Platform:
     * Solaris 10 with patch 120012-04 or later and without patch
       127954-03

   NOTE: Solaris 8 and 9 are not impacted by this issue.

   A system is only impacted by this issue if both the following are
   true:

   a) The system is acting as a NFS server, is sharing root access to
   remote clients using the "root=" option and is mounting the file
   systems either as read-only ("ro=" option) or as read-write ("rw="
   option). See share_nfs(1M) for information on file system sharing
   options. To list all file systems shared by an NFS server, the
   '/usr/sbin/share' command may be used as in the following example:
    $ share
    /NFSTEST   root=hostname   ""

   b) Either the 'ipnodes' OR the 'hosts' entry (OR both these entries)
   in /etc/nsswitch.conf have only "files" used to define the source. The
   following command may be executed to check these entries in
   /etc/nsswitch.conf:
    $ egrep '^ipnodes|^hosts' /etc/nsswitch.conf
    hosts:      files nisplus dns [NOTFOUND=return] files
    ipnodes:    nisplus [NOTFOUND=return] files

3. Symptoms

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

4. Relief/Workaround

   A) To work around this issue, patch 120011-04 or later (SPARC) or
   patch 120012-04 or later (x86) may be removed using the patchrm(1M)
   command.

   Note however that these patches cannot be removed on Solaris 10 8/07
   systems, as they are part of the initial installation of Solaris 10
   8/07.

   B) Alternatively, this issue can be avoided by adding another name
   service for hosts and ipnodes in /etc/nsswitch.conf. For example:
    $ egrep '^ipnodes|^hosts' /etc/nsswitch.conf
    hosts:      files nis
    ipnodes:    files nis

   C) This issue can also be avoided by disabling the nscd(1M) daemon on
   the NFS server. Disabling the nscd daemon may slow responses to name
   service requests on the NFS server. The nscd daemon may be disabled by
   running the following command (as 'root' user):
    # svcadm disable svc:/system/name-service-cache:default

5. Resolution

   This issue is addressed in the following releases:

   SPARC Platform
     * Solaris 10 with patch 127111-05 or later

   x86 Platform
     * Solaris 10 with patch 127954-03 or later

Change History

   14-Dec-2007:
     * Updated Contributing Factors section

   21-Dec-2007:
     * Updated Impact and Contributing Factors sections for clarification

   08-Jan-2008:
     * Updated Impact section

   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 2000-2006 Sun Microsystems, Inc., 4150 Network Circle, Santa
   Clara, CA 95054 U.S.A. All rights reserved

- --------------------------END INCLUDED TEXT--------------------

You have received this e-mail bulletin as a result of your organisation's
registration with AusCERT. The mailing list you are subscribed to is
maintained within your organisation, so if you do not wish to continue
receiving these bulletins you should contact your local IT manager. If
you do not know who that is, please send an email to auscert@auscert.org.au
and we will forward your request to the appropriate person.

NOTE: Third Party Rights
This security bulletin is provided as a service to AusCERT's members.  As
AusCERT did not write the document quoted above, AusCERT has had no control
over its content. The decision to follow or act on information or advice
contained in this security bulletin is the responsibility of each user or
organisation, and should be considered in accordance with your organisation's
site policies and procedures. AusCERT takes no responsibility for consequences
which may arise from following or acting on information or advice contained in
this security bulletin.

NOTE: This is only the original release of the security bulletin.  It may
not be updated when updates to the original are made.  If downloading at
a later date, it is recommended that the bulletin is retrieved directly
from the author's website to ensure that the information is still current.

Contact information for the authors of the original document is included
in the Security Bulletin above.  If you have any questions or need further
information, please contact them directly.

Previous advisories and external security bulletins can be retrieved from:

        http://www.auscert.org.au/render.html?cid=1980

If you believe that your computer system has been compromised or attacked in 
any way, we encourage you to let us know by completing the secure National IT 
Incident Reporting Form at:

        http://www.auscert.org.au/render.html?it=3192

===========================================================================
Australian Computer Emergency Response Team
The University of Queensland
Brisbane
Qld 4072

Internet Email: auscert@auscert.org.au
Facsimile:      (07) 3365 7031
Telephone:      (07) 3365 4417 (International: +61 7 3365 4417)
                AusCERT personnel answer during Queensland business hours
                which are GMT+10:00 (AEST).
                On call after hours for member emergencies only.
===========================================================================

-----BEGIN PGP SIGNATURE-----
Comment: http://www.auscert.org.au/render.html?it=1967

iQCVAwUBR4WgYih9+71yA2DNAQK5EgP/WQTlYLVmKBNgjyO0h02LsQm8+0phGbYa
+aXJnelfWBv9qURZaSkib9EvgO3DNXWZLc5WHh3DbnGYOW9gi/L41GUcZCBL0EhF
SzN/klUCAqFnILTU+Be/QAWLZRlvD3ySg5VdPTv4ygKn0Xi8WgMRPGisTiQX8+ol
ro+7k84bCVs=
=DI/H
-----END PGP SIGNATURE-----