IBM SECURITY ADVISORY First Issued: Thu Sept 13 13:43:29 CDT 2012 | Updated: Wed Sept 26 13:25:50 CDT 2012 | Updated: Removed the cve.mitre.org reference | 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/nfsv4_advisory1.asc ftp://aix.software.ibm.com/aix/efixes/security/nfsv4_advisory1.asc =============================================================================== VULNERABILITY SUMMARY VULNERABILITY: AIX NFSv4 vulnerability PLATFORMS: AIX 5.3, 6.1, and 7.1 releases SOLUTION: Apply the fix as described below. THREAT: See below CVE Numbers: CVE-2012-4817 CVSS=5 Reboot required? YES Workarounds? NO Protected by FPM? NO Protected by SED? NO =============================================================================== DETAILED INFORMATION I. DESCRIPTION GID in NFSv4 is loosely enforced. II. CVSS CVSS Base Score: 5 CVSS Temporal Score: See http://xforce.iss.net/xforce/xfdb/78431 for the current score CVSS Environmental Score*: Undefined CVSS String: (AV:N/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.net.nfs.client The following fileset levels are vulnerable: AIX Fileset Lower Level Upper Level KEY ------------------------------------------------------------------- bos.net.nfs.client 5.3.12.0 5.3.12.5 key_w_fs bos.net.nfs.client 6.1.6.0 6.1.6.17 key_w_fs bos.net.nfs.client 6.1.7.0 6.1.7.2 key_w_fs bos.net.nfs.client 7.1.0.0 7.1.0.20 key_w_fs bos.net.nfs.client 7.1.1.0 7.1.1.3 key_w_fs IV. SOLUTIONS A. APARS IBM has assigned the following APARs to this problem: AIX Level APAR number Availability KEY ---------------------------------------------------------------- 5.3.12 IV17855 Available SP6 key_w_apar 6.1.6 IV10327 Available SP7 key_w_apar 6.1.7 IV11629 Available SP3 key_w_apar 7.1.0 IV26436 12/12/12 sp8 key_w_apar 7.1.1 IV12169 Available SP4 key_w_apar Subscribe to the APARs here: http://www.ibm.com/support/docview.wss?uid=isg1IV17855 http://www.ibm.com/support/docview.wss?uid=isg1IV10327 http://www.ibm.com/support/docview.wss?uid=isg1IV11629 http://www.ibm.com/support/docview.wss?uid=isg1IV26436 http://www.ibm.com/support/docview.wss?uid=isg1IV12169 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/nfsv4_fix1.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 ------------------------------------------------------------------- 7.1.0.7 IV26436s07.120907.epkg.Z key_w_fix VIOS Level Interim Fix (*.Z) ------------------------------------------------------------------- 2.2.1.4-FP-25 SP-02 Included in current SP To extract the fixes from the tar file: tar xvf nfsv4_fix1.tar cd nfsv4_fix1 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 ------------------------------------------------------------------ 8f42e3c1a5eb3a0d73d7be8d38265544f9abd866 IV26436s07.120907.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 security-alert@austin.ibm.com 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: security-alert@austin.ibm.com 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: security-alert@austin.ibm.com B. Download the key from our web page: 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/78431 CVE-2012-4817: http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2012-4817 *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.