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AUSCERT External Security Bulletin Redistribution
ESB-2009.1546.2
Two Security Vulnerabilities in SAMBA(7) May Allow Unauthorized Access to
the Remote Root Filesystem or May Lead to a Denial of
Service (DoS) Condition
16 February 2010
===========================================================================
AusCERT Security Bulletin Summary
---------------------------------
Product: SAMBA(7)
Publisher: Sun Microsystems
Operating System: Solaris 9 Operating System
Solaris 10 operating System
OpenSolaris
Impact/Access: Unauthorised Access -- Existing Account
Denial of Service -- Existing Account
Resolution: Patch/Upgrade
CVE Names: CVE-2009-2906 CVE-2009-2813
Reference: ESB-2009.1532
ESB-2009.1451
ESB-2009.1412
Original Bulletin:
http://sunsolve.sun.com/search/printfriendly.do?assetkey=1-66-271069-1
Revision History: February 16 2010: Final patches released, updated
Contributing Factors and Resolution
sections, now Resolved
November 19 2009: Initial Release
- --------------------------BEGIN INCLUDED TEXT--------------------
Category : Security
Release Phase : Resolved
Bug Id : 6888097
Product : SAMBA
Solaris 9 Operating System
Solaris 10 Operating System
OpenSolaris
Date of Workaround Release : 17-Nov-2009
Date of Resolved Release : 11-Feb-2010
Two Security Vulnerabilities in SAMBA(7) May Allow Unauthorized Access to the
Remote Root Filesystem or May Lead to a Denial of Service (DoS) Condition
1. Impact
Two security vulnerabilities in SAMBA(7) may result in one or both of the
following issues:
1. A remote unprivileged user with a valid SAMBA account may gain unauthorized
access to the remote root file system. This issue is referenced in the
following CVE document:
http://www.samba.org/samba/security/CVE-2009-2813.html
2. A remote unprivileged user on an authenticated SAMBA connection may cause
a Denial of Service (DoS) condition via specially crafted SMB requests. This
issue is referenced in the following CVE document:
http://www.samba.org/samba/security/CVE-2009-2906.html
2. Contributing Factors
These issues can occur in the following releases:
SPARC Platform
* Solaris 9 without patch 114684-15
* Solaris 10 without patch 119757-17
* OpenSolaris based upon builds snv_01 through 126
X86 Platform
* Solaris 9 without patch 114685-15
* Solaris 10 without patch 119758-17
* OpenSolaris based upon builds snv_01 through 126
running SAMBA software 3.0.36 and earlier.
Notes:
1. Solaris 8 does not include the SAMBA software and is not affected by
this issue.
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 run:
$ uname -v
snv_125
3. These issues can only occur if the following conditions are true:
- - The system is configured as a SAMBA server
- - The version of SAMBA installed is earlier than 3.0.37
To determine if a system is configured as a SAMBA server, the following
command can be run to check for processes related to SAMBA:
% ps -ef | grep mbd
root 317 1 0 May 26 ? 0:01 /usr/sfw/sbin/smbd -D
root 325 317 0 May 26 ? 0:00 /usr/sfw/sbin/smbd -D
root 314 1 0 May 26 ? 0:27 /usr/sfw/sbin/nmbd -D
root 28369 17382 0 23:17:46 pts/2 0:00 grep mbd
If the output shows "smbd" or "nmbd" running as a daemon (with the -D
parameter), the system is configured as a SAMBA server.
To determine the SAMBA version, the following command can be run:
$ /usr/sfw/sbin/smbd -V
Version 3.0.28
4. The issue described in CVE-2009-2813 only occurs for users with an empty
home directory and if automated [homes] share is enabled in SAMBA.
To determine which users have an empty home directory, the following command
can be run:
$ getent passwd | /usr/bin/grep '^[^:]*:[^:]*:[^:]*:[^:]*:[^:]*::'
joe:x:62237:6883:Test User::/bin/ksh
The above example shows that the user 'Test User' has an empty home directory.
To determine if automated [homes] share is enabled in SAMBA, the following
command can be run:
$ /usr/bin/grep '\[homes\]' /etc/sfw/smb.conf || echo "Automated [homes] share
was not enabled"
3. Symptoms
Should the issue described in CVE-2009-2906 occur, the smbd(1M) daemon will
consume a large amount of CPU resources. The prstat(1M) command may be used to
verify the CPU usage of the smbd(1M) process as indicated in the following
example:
=========================Example output: ===================================
PID USERNAME SIZE RSS STATE PRI NICE TIME CPU PROCESS/NLWP
28452 root 11M 1172K sleep 59 0 1:09:11 43% smbd/1
...
============================================================================
On machines with multiple CPUs, the smbd(1M) daemon utilizes a large amount of
resources on a single CPU.
There are no predictable symptoms to indicate the issue described in
CVE-2009-2813 is exploited to gain unauthorized access to the remote root
filesystem.
4. Workaround
To work around the issue described in CVE-2009-2813, the SAMBA service may be
configured to disable the automated [homes] share. This may be done by
removing the entry '[homes]' from '/etc/sfw/smb.conf' as follows:
On Solaris 9:
1. Stop the SAMBA service:
# /etc/init.d/samba stop
2. Edit the '/etc/sfw/smb.conf' file and remove the entry '[homes]'
3. Start the SAMBA service again:
# /etc/init.d/samba start
On Solaris 10:
1. Stop the SAMBA service:
# svcadm disable samba
2. Edit the '/etc/sfw/smb.conf' file and remove the entry '[homes]'
3. Start the SAMBA service again:
# svcadm enable samba
To work around the issue described in CVE-2009-2906, disable the SAMBA
service by using the following commands:
On Solaris 9:
# /etc/init.d/samba stop
On Solaris 10:
# svcadm disable samba
5. Resolution
This issue is addressed in the following releases:
SPARC Platform
* Solaris 9 with patch 114684-15 or later
* Solaris 10 with patch 119757-17 or later
* OpenSolaris based upon builds snv_127 or later
x86 Platform
* Solaris 9 with patch 114685-15 or later
* Solaris 10 with patch 119758-17 or later
* OpenSolaris based upon builds snv_127 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.
Modification History
05-Feb-2010: Updated Contributing Factors and Resolution sections for Solaris
9 patches
11-Feb-2010: Final patches released, updated Contributing Factors and
Resolution sections, now Resolved
- --------------------------END INCLUDED TEXT--------------------
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