-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 IBM SECURITY ADVISORY First Issued: Tue May 8 15:22:37 CDT 2012 | Update: Thu May 10 12:12:04 CDT 2012 | Corrected APAR Numbers | Update: Fri May 11 17:24:08 CDT 2012 | Corrected ifix name The most recent version of this document is available here: http://aix.software.ibm.com/aix/efixes/security/rpc_advisory.asc =============================================================================== VULNERABILITY SUMMARY VULNERABILITY: Vulnerability in AIX RPC PLATFORMS: AIX 5.3, 6.1, and 7.1 releases SOLUTION: Apply the fix as described below. THREAT: RPC portmapper Access Restriction Bypass CVE Number: CVE-2011-0321 Reboot required? YES Workarounds? YES Protected by FPM? NO Protected by SED? NO =============================================================================== DETAILED INFORMATION I. DESCRIPTION Vulnerability which allows remote attackers to (1) register or (2) unregister RPC services, and consequently cause a denial of service or obtain sensitive information from interprocess communication, via crafted UDP packets containing service commands. Note: The ifix provided also contains the fix for CVE-2012-0194 and CVE-2011-1385 since they affect the same fileset. See the following for CVE-2012-0194: http://aix.software.ibm.com/aix/efixes/security/large_send_advisory.asc CVE-2011-1385: http://aix.software.ibm.com/aix/efixes/security/icmp_advisory.asc II. CVSS CVSS Base Score: 6.4 CVSS Temporal Score: See http://xforce.iss.net/xforce/xfdb/64997 for the current score CVSS Environmental Score*: Undefined CVSS String: (AV:N/AC:L/Au:N/C:P/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.tcp.client The following fileset levels are vulnerable: AIX Fileset Lower Level Upper Level ------------------------------------------------ bos.net.tcp.client 5.3.12.0 5.3.12.5 bos.net.tcp.client 6.1.5.0 6.1.5.7 bos.net.tcp.client 6.1.6.0 6.1.6.16 bos.net.tcp.client 6.1.7.0 6.1.7.1 bos.net.tcp.client 7.1.0.0 7.1.0.17 bos.net.tcp.client 7.1.1.0 7.1.1.1 IV. SOLUTIONS A. APARS IBM has assigned the following APARs to this problem: AIX Level APAR number Availability --------------------------------------------------- | 5.3.12 IV17941 6/13/12 sp6 | 6.1.5 IV07315 Available | 6.1.6 IV13543 Available | 6.1.7 IV08677 Available | 7.1.0 IV14728 Available | 7.1.1 IV08787 Available Subscribe to the APARs here: | http://www.ibm.com/support/docview.wss?uid=isg1IV17941 | http://www.ibm.com/support/docview.wss?uid=isg1IV07315 | http://www.ibm.com/support/docview.wss?uid=isg1IV13543 | http://www.ibm.com/support/docview.wss?uid=isg1IV08677 | http://www.ibm.com/support/docview.wss?uid=isg1IV14728 | http://www.ibm.com/support/docview.wss?uid=isg1IV08787 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/rpc_fix.tar The link above is to a tar file containing this signed advisory, fix packages, and PGP 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) ------------------------------------------------------------------- | 5.3.12.5 IV13827m05.120418.epkg.Z 6.1.5.8 APAR Available 6.1.6.7 APAR Available 6.1.7.2 APAR Available 7.1.0.5 APAR Available 7.1.1.2 APAR Available VIOS Level Interim Fix (*.Z) ------------------------------------------------------------------- 2.2.1.3 FP25 SP0 Fix included in this level To extract the fixes from the tar file: tar xvf rpc_fix.tar cd rpc_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 ------------------------------------------------------------------ 022795761c426c52f674a17215097dcebe97b73b IV13827m05.120418.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 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 at security-alert@austin.ibm.com and describe the discrepancy. 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; thus, IBM does not warrant the fully correct functionality of an interim fix. 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 Adjust the lowest value from the common path MTUs table based on customer configuration. Turn off large send function (may have performance impact) Turn off path MTU discovery (may have performance impact) VI. OBTAINING FIXES AIX security fixes can be downloaded from: 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. VII. CONTACT INFORMATION If you would like to receive AIX Security Advisories via email, 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 request 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 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. VIII. REFERENCES: 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/64997 CVE-2011-0321: http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2011-0321 *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. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.7 (AIX) iD8DBQFPrZqJ4fmd+Ci/qhIRAkP8AJwLxypvoftuvfSFQeCK6RNpQxIZJwCeJDh1 luL2UVBtxSktJBqv1bgy9uU= =1Prc -----END PGP SIGNATURE-----