IBM SECURITY ADVISORY

First Issued: Fri Sept 28 13:02:02 CDT 2012
| Updated: Wed Dec 12 14:46:21 CDT 2012
| Update: New ifixes for the latest SP’s
| Updated: Thu Dec 12 12:55:11 CST 2013
| Update: 1. Added KEYs for parsing purposes
| 2. Moved to OpenSSL signature

The most recent version of this document is available here:
http://aix.software.ibm.com/aix/efixes/security/fuser_advisory.asc
ftp://aix.software.ibm.com/aix/efixes/security/fuser_advisory.asc

                       VULNERABILITY SUMMARY

VULNERABILITY: AIX fuser vulnerability

PLATFORMS: 6.1 and 7.1 releases

SOLUTION: Apply the fix as described below.

THREAT: See below

CVE Numbers: CVE-2012-4833 CVSS=2.1

Reboot required? NO
Workarounds? NO
Protected by FPM? NO
Protected by SED? NO

===============================================================================
DETAILED INFORMATION

I. DESCRIPTION

IBM AIX is vulnerable to a denial of service, caused by improper 
restrictions on the fuser command. A local attacker could exploit this 
vulnerability via the -k argument to kill a process of another user.

II. CVSS

CVSS Base Score: 2.1
CVSS Temporal Score: See http://xforce.iss.net/xforce/xfdb/78907 for the 
current score 
CVSS Environmental Score*: Undefined
CVSS String: (AV:L/AC:L/Au:N/C:N/I:N/A:P)

III. PLATFORM VULNERABILITY ASSESSMENT

Note: To use the following commands on VIOS you must first
execute:

oem_setup_env

To determine if your system is vulnerable, execute the following
command:

lslpp -L bos.rte.filesystem

The following fileset levels are vulnerable:

AIX Fileset         Lower Level   Upper Level  KEY
--------------------------------------------------------

| bos.rte.filesystem 6.1.6.0 6.1.6.20 key_w_fs
| bos.rte.filesystem 6.1.7.0 6.1.7.17 key_w_fs
| bos.rte.filesystem 6.1.8.0 6.1.8.0 key_w_fs
| bos.rte.filesystem 7.1.0.0 7.1.0.19 key_w_fs
| bos.rte.filesystem 7.1.1.0 7.1.1.17 key_w_fs
| bos.rte.filesystem 7.1.2.0 7.1.2.0 key_w_fs

IV. SOLUTIONS

A. APARS

    IBM has assigned the following APARs to this problem:

    AIX Level   APAR      Availability   SP      KEY
    ---------------------------------------------------

| 6.1.6 IV28151 03/29/13 sp11 key_w_apar
| 6.1.7 IV28749 03/29/13 sp7 key_w_apar
| 6.1.8 IV29289 03/08/13 sp2 key_w_apar
| 7.1.0 IV28754 05/02/13 sp9 key_w_apar
| 7.1.1 IV28756 05/02/13 sp7 key_w_apar
| 7.1.2 IV29207 03/08/13 sp2 key_w_apar

    Subscribe to the APARs here:

    http://www.ibm.com/support/docview.wss?uid=isg128151
    http://www.ibm.com/support/docview.wss?uid=isg128749

| http://www.ibm.com/support/docview.wss?uid=isg129289
http://www.ibm.com/support/docview.wss?uid=isg128754
http://www.ibm.com/support/docview.wss?uid=isg128756
| http://www.ibm.com/support/docview.wss?uid=isg129207

    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 available.  The fixes can be downloaded via ftp
    from:

    ftp://aix.software.ibm.com/aix/efixes/security/fuser_fix.tar

    The link above is to a tar file containing this signed
    advisory, fix packages, and OpenSSL signatures for each package.
    The fixes below include prerequisite checking. This will
    enforce the correct mapping between the fixes and AIX
    Technology Levels.

    AIX Level    Interim Fix (*.Z)            KEY
    -------------------------------------------------------------------
    6.1.6.9      IV28151s09.120926.epkg.Z     key_w_fix

| 6.1.6.10 IV28151sAa.121207.epkg.Z key_w_fix
6.1.7.5 IV28749s05.120926.epkg.Z key_w_fix
| 6.1.7.6 IV28749s6a.121207.epkg.Z key_w_fix
| 6.1.8.0 IV29289s1a.121203.epkg.Z key_w_fix
| 6.1.8.1 IV29289s1a.121203.epkg.Z key_w_fix
7.1.0.7 IV28754s07.120926.epkg.Z key_w_fix
| 7.1.0.8 IV28754s8a.121207.epkg.Z key_w_fix
7.1.1.5 IV28756s05.120926.epkg.Z key_w_fix
| 7.1.1.6 IV28756s6a.121210.epkg.Z key_w_fix
| 7.1.2.1 IV29207s0a.121206.epkg.Z key_w_fix
| 7.1.2.2 IV29207s0a.121206.epkg.Z key_w_fix

    VIOS Level                    Interim Fix (*.Z)
    -------------------------------------------------------------------
    VIOS 2.2.1.4-FP-25 SP-02      IV28749s04.120926.epkg.Z     

    To extract the fixes from the tar file:

    tar xvf fuser_fix.tar 
    cd fuser_fix

    Verify you have retrieved the fixes intact:

    The checksums below were generated using the
    "csum -h SHA1" (sha1sum) command is the followng:

    csum -h SHA1 (sha1sum)                    filename
    ------------------------------------------------------------------
    c607d32b2e12aa840060001f35526501b976490f  IV28151s09.120926.epkg.Z

| d9de33f0c5d50a4ee81df53fe8d4578e1e421be1 IV28151sAa.121207.epkg.Z
a0b99ea910bece90a907c2a111d146fa16d64404 IV28749s05.120926.epkg.Z
| 73b103ace5bb1a90cb76c06c50c340b4f1200ca7 IV28749s6a.121207.epkg.Z
| 7b93e94617ccc73eb102f16b3e7d8d1e83ada530 IV29289s1a.121203.epkg.Z
c8fc384fa720282efe92acb584300ee878c7c926 IV28754s07.120926.epkg.Z
| 1a3f25cb2f3f8789b54679c2acf2098cf115517a IV28754s8a.121207.epkg.Z
feae51894146d83d589313bf829caf11df30882f IV28756s05.120926.epkg.Z
| c905b3c90bf21a02cd5aee3552be5a3e4a90fe1b IV28756s6a.121210.epkg.Z
| 2e47667cbcb9466456ff8a4bfa2b5dccc3670b35 IV29207s0a.121206.epkg.Z
1e0a8950b6d69c697764080c741af01e7a300b0a IV28749s04.120926.epkg.Z

    To verify the sum, use the text of this advisory as input to sha1sum.
    For example:

    csum -h SHA1 -i Advisory.asc
    sha1sum -c Advisory.asc

    These sums should match exactly. The OpenSSL 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 at
    [email protected] and describe the discrepancy.

    openssl dgst -sha1 -verify AIX_PSIRT_pub.asc -signature file.asc.sig file.asc

C. FIX AND INTERIM 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.

    Interim fixes have had limited functional and regression
    testing but not the full regression testing that takes place
    for Service Packs; however, IBM does fully support them.

    Interim fix management documentation can be found at:

    http://www14.software.ibm.com/webapp/set2/sas/f/aix.efixmgmt/home.html

    To preview an interim fix installation:

    emgr -e ipkg_name -p         # where ipkg_name is the name of the
                                 # interim fix package being previewed.

    To install an interim fix package:

    emgr -e ipkg_name -X         # where ipkg_name is the name of the
                                 # interim fix package being installed.

V. WORKAROUNDS

 There are no workarounds.

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:

    [email protected]

 To obtain the OpenSSL public key that can be used to verify the
 signed advisories and ifixes:

     Download the key from our web page:

     http://www.ibm.com/systems/resources/systems_p_os_aix_security_pubkey.txt

To obtain the PGP public key that can be used to communicate
securely with the AIX Security Team you can either:

    A. Send an email with "get key" in the subject line to:

        [email protected]

    B. Download the key from a PGP Public Key Server. The key ID is:

        0x28BFAA12

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

IBM discovered and fixed this vulnerability as part of its
commitment to secure the AIX operating system.

VIII. REFERENCES:

Note: Keywords labeled as KEY in this document are used for parsing purposes.

Complete CVSS Guide: http://www.first.org/cvss/cvss-guide.html
On-line Calculator V2: http://nvd.nist.gov/cvss.cfm?calculator&adv&version=2
X-Force Vulnerability Database: http://xforce.iss.net/xforce/xfdb/78907
CVE-2012-4833: https://vulners.com/cve/CVE-2012-4833

*The CVSS Environment Score is customer environment specific and will
ultimately impact the Overall CVSS Score. Customers can evaluate the
impact of this vulnerability in their environments by accessing the links
in the Reference section of this Flash.

Note: According to the Forum of Incident Response and Security Teams
(FIRST), the Common Vulnerability Scoring System (CVSS) is an "industry
open standard designed to convey vulnerability severity and help to
determine urgency and priority of response." IBM PROVIDES THE CVSS SCORES
"AS IS" WITHOUT WARRANTY OF ANY KIND, INCLUDING THE IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. CUSTOMERS ARE
RESPONSIBLE FOR ASSESSING THE IMPACT OF ANY ACTUAL OR POTENTIAL SECURITY
VULNERABILITY.