Protect yourself against future threats.
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
===========================================================================
AUSCERT External Security Bulletin Redistribution
ESB-2009.1356.2
AIX NFSv4 nfs_portmon and Kerberos vulnerabilities
2 October 2009
===========================================================================
AusCERT Security Bulletin Summary
---------------------------------
Product: NFSv4
Kerberos
Publisher: IBM
Operating System: AIX
Impact/Access: Unauthorised Access -- Remote/Unauthenticated
Resolution: Patch/Upgrade
CVE Names: CVE-2009-3517 CVE-2009-3516
Revision History: October 2 2009: Added CVE References
September 30 2009: Initial Release
- --------------------------BEGIN INCLUDED TEXT--------------------
- -----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
IBM SECURITY ADVISORY
First Issued: Tue Sep 29 12:42:51 CDT 2009
The most recent version of this document is available here:
http://aix.software.ibm.com/aix/efixes/security/nfs4_advisory.asc
or
ftp://aix.software.ibm.com/aix/efixes/security/nfs4_advisory.asc
VULNERABILITY SUMMARY
VULNERABILITY: AIX NFSv4 nfs_portmon and Kerberos vulnerabilities.
PLATFORMS: AIX 5.3, 6.1
SOLUTION: Apply the fix as described below.
THREAT: A local user can gain unauthorized access to
Kerberized AIX NFSv4 shares. A remote user can gain
unauthorized network access to AIX NFSv4 shares
protected by the nfs_portmon tunable.
CERT VU Number: n/a
CVE Number: n/a
Reboot required? YES*
Workarounds? NO
Protected by FPM? NO
Protected by SED? NO
* For the nfs_portmon fix, the machine must be rebooted to reload the
NFS kernel extensions. For the Kerberos fix, the gssd daemon must
be restarted.
DETAILED INFORMATION
I. DESCRIPTION
There are two security vulnerabilities in the AIX NFSv4 (Network
File System version 4) implementation.
The first vulnerability is an error in the handling of the NFSv4
Kerberos credential cache. The successful exploitation of this
vulnerability allows a local user to access Kerberized network
shares without authorization.
The second vulnerability is that the nfs_portmon tunable is not
utilized correctly in NFSv4. The successful exploitation of this
vulnerability allows a remote user to access network shares
protected by nfs_portmon without authorization.
The following commands are vulnerable:
/usr/sbin/gssd
/usr/lib/drivers/nfs.ext
II. PLATFORM VULNERABILITY ASSESSMENT
To determine if your system is vulnerable, execute the following
command:
lslpp -L bos.net.nfs.client
The following fileset levels are vulnerable:
AIX Fileset Lower Level Upper Level
---------------------------------------------------
bos.net.nfs.client all earlier versions of 5.3
bos.net.nfs.client 5.3.7.0 5.3.7.8
bos.net.nfs.client 5.3.8.0 5.3.8.6
bos.net.nfs.client 5.3.9.0 5.3.9.2
bos.net.nfs.client 6.1.0.0 6.1.0.8
bos.net.nfs.client 6.1.1.0 6.1.1.4
bos.net.nfs.client 6.1.2.0 6.1.2.3
III. SOLUTIONS
A. APARS
IBM has assigned the following APARs to this problem:
AIX Level APAR number Availability
----------------------------------------------------
5.3.7 IZ50496 Now (SP9)
5.3.8 IZ50444 Now (SP7)
5.3.9 IZ50399 Now (SP4)
6.1.0 IZ49278 Now (SP9)
6.1.1 IZ49096 Now (SP5)
6.1.2 IZ49024 Now (SP4)
Subscribe to the APARs here:
http://www.ibm.com/support/docview.wss?uid=isg1IZ50496
http://www.ibm.com/support/docview.wss?uid=isg1IZ50444
http://www.ibm.com/support/docview.wss?uid=isg1IZ50399
http://www.ibm.com/support/docview.wss?uid=isg1IZ49278
http://www.ibm.com/support/docview.wss?uid=isg1IZ49096
http://www.ibm.com/support/docview.wss?uid=isg1IZ49024
By subscribing, you will receive periodic email alerting you
to the status of the APAR, and a link to download the fix once
it becomes available.
B. FIXES
Fixes are now available. The fixes can be downloaded from:
http://aix.software.ibm.com/aix/efixes/security/nfs4_fix.tar
ftp://aix.software.ibm.com/aix/efixes/security/nfs4_fix.tar
The links above are to a tar file containing this signed
advisory, fix packages, and PGP signatures for each package.
AIX Level Fix
----------------------------------------------------
5.3.7 bos.net.nfs.client.5.3.7.9.U
5.3.8 bos.net.nfs.client.5.3.8.7.U
5.3.9 bos.net.nfs.client.5.3.9.3.U
6.1.0 bos.net.nfs.client.6.1.0.9.U
6.1.1 bos.net.nfs.client.6.1.1.5.U
6.1.2 bos.net.nfs.client.6.1.2.4.U
To extract the fixes from the tar file:
tar xvf nfs4_fix.tar
cd nfs4_fix
Verify you have retrieved the fixes intact:
The checksums below were generated using the "csum -h SHA1"
(sha1sum) commands and are as follows:
csum -h SHA1 (sha1sum) filename
----------------------------------------------------------------------
6498591e2a75f5081f30487220ef205649be34a3 bos.net.nfs.client.5.3.7.9.U
55ff5576fccb052c05d0432250619ef9e3bd1fe1 bos.net.nfs.client.5.3.8.7.U
c98585939e0bf02c5b88adbb0bbc48c52d261e07 bos.net.nfs.client.5.3.9.3.U
d0d3f99ea11fcae97bacd782b904363f60191351 bos.net.nfs.client.6.1.0.9.U
5c73c73eca95fa782f82ade9c5b56f64217113ab bos.net.nfs.client.6.1.1.5.U
a3251008ee0e4e4a67b7e9beff5a0d9550407fcf bos.net.nfs.client.6.1.2.4.U
To verify the sums, use the text of this advisory as input to
csum or sha1sum. For example:
csum -h SHA1 -i Advisory.asc
sha1sum -c Advisory.asc
These sums should match exactly. The PGP signatures in the tar
file and on this advisory can also be used to verify the
integrity of the fixes. If the sums or signatures cannot be
confirmed, contact IBM AIX Security and describe the
discrepancy at the following address:
security-alert@austin.ibm.com
C. FIX INSTALLATION
IMPORTANT: If possible, it is recommended that a mksysb backup
of the system be created. Verify it is both bootable and
readable before proceeding.
To preview a fix installation:
installp -a -d fix_name -p all # where fix_name is the name of the
# fix package being previewed.
To install a fix package:
installp -a -d fix_name -X all # where fix_name is the name of the
# fix package being installed.
IV. WORKAROUNDS
There are no workarounds.
V. OBTAINING FIXES
AIX security fixes can be downloaded from:
http://aix.software.ibm.com/aix/efixes/security
or
ftp://aix.software.ibm.com/aix/efixes/security
AIX fixes can be downloaded from:
http://www.ibm.com/eserver/support/fixes/fixcentral/main/pseries/aix
NOTE: Affected customers are urged to upgrade to the latest
applicable Technology Level and Service Pack.
VI. CONTACT INFORMATION
If you would like to receive AIX Security Advisories via email,
please visit:
http://www.ibm.com/systems/support
and click on the "My notifications" link.
To view previously issued advisories, please visit:
http://www14.software.ibm.com/webapp/set2/subscriptions/pqvcmjd
Comments regarding the content of this announcement can be
directed to:
security-alert@austin.ibm.com
To obtain the PGP public key that can be used to communicate
securely with the AIX Security Team you can either:
A. Download the key from our web page:
http://www.ibm.com/systems/resources/systems_p_os_aix_security_pgpkey.txt
B. Download the key from a PGP Public Key Server. The key ID is:
0xADA6EB4D
Please contact your local IBM AIX support center for any
assistance.
eServer is a trademark of International Business Machines
Corporation. IBM, AIX and pSeries are registered trademarks of
International Business Machines Corporation. All other trademarks
are property of their respective holders.
VII. ACKNOWLEDGMENTS
The vulnerabilties were reported by Anton Lundin.
- -----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.7 (AIX)
iD8DBQFKwkdYP9Qud62m600RAjxsAJwNxkpMReX6iAv222wuUJLULzEJwQCeLahd
SFVrhFko9oMabu83JeAiYL8=
=Dz6F
- -----END PGP SIGNATURE-----
- --------------------------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
iD8DBQFKxVs7NVH5XJJInbgRAuHIAJ4jLTsOGGgu/H8VU+rcnhFgtvvNcwCfbxUZ
nNZQt6DfVxVXmY9WEMq+K74=
=wuMJ
-----END PGP SIGNATURE-----