__________________________________________________________ The U.S. Department of Energy Computer Incident Advisory Capability ___ __ __ _ ___ / | /_\ / \___ __|__ / \ \___ __________________________________________________________ INFORMATION BULLETIN IBM AIX 5.3 NIS Client Vulnerability [IBM Security Advisory Issued 1/30/2005] February 1, 2005 18:00 GMT Number P-118 ______________________________________________________________________________ PROBLEM: An undisclosed vulnerability was discovered in IBM AIX 5.3 when it is configured as an NIS client. PLATFORM: IBM AIX 5.3 when configured as NIS client (Versions prior to 5.3 are not affected) DAMAGE: A remote user may gain root privileges. It is also possible for a local attacker to exploit this vulnerability. SOLUTION: Install the available security update. ______________________________________________________________________________ VULNERABILITY The risk is MEDIUM. An authenticated attacker may gain root ASSESSMENT: privileges. ______________________________________________________________________________ LINKS: CIAC BULLETIN: http://www.ciac.org/ciac/bulletins/p-118.shtml ORIGINAL BULLETIN: IBM Security Advisory Issues 1/30/2005 ftp://aix.software.ibm.com/aix/efixes/security/nis_efix.tar.Z ADDITIONAL LINK: Secunia Advisory SA14095 http://secunia.com/advisories/14095/ ______________________________________________________________________________ [***** Start IBM Security Advisory Issued 1/30/2005 *****] IBM SECURITY ADVISORY First Issued: Sun Jan 30 15:30:27 CST 2005 =========================================================================== VULNERABILITY SUMMARY VULNERABILITY: A remote user may gain root access to a system configured as a NIS client. PLATFORMS: AIX 5.3. SOLUTION: Apply the workaround, efix or APAR as described below. THREAT: A remote user may gain root access to a system configured as a NIS client. CERT VU Number: N/A CVE Number: N/A =========================================================================== DETAILED INFORMATION I. Description =============== A vulnerability was discovered that can be exploited by a remote user to gain root privileges. Note that it is also possible for a local attacker to exploit this vulnerability. This vulnerability only affects AIX 5.3 when configured as a NIS client. Versions of AIX prior to AIX 5.3 are not affected by this issue. II. Impact ========== A remote attacker may gain root access to a system configured as a NIS client. III. Solutions =============== A. Official Fix IBM provides the following fixes: APAR number for AIX 5.3.0: IY67248 (available approx. 05/19/04) NOTE: Affected customers are urged to upgrade to 5.3.0 at the latest maintenance level. B. Emergency Fix Efixes are available for AIX 5.3.0. The efixes can be downloaded via ftp from: ftp://aix.software.ibm.com/aix/efixes/security/nis_efix.tar.Z nis_efix.tar.Z is a compressed tarball containing this advisory, two efix packages for 5.3.0 and a cleartext PGP signature for each efix package. The efix package named IY67248_01.050128.epkg.Z is for AIX 5.3.0 with no maintenance level applied. This efix has the filesets bos.rte.libc.5.3.0.5 and bos.rte.security.5.3.0.5 as prerequisites and will not install unless these prerequisites are installed on the system. The efix package named IY67248_00.050128.epkg.Z is for AIX 5.3.0 with maintenance level one applied. This efix has the filesets bos.rte.libc.5.3.0.11 and bos.rte.security.5.3.0.10 as prerequisites and will not install unless these prerequisites are installed on the system. Verify you have retrieved the efixes intact: --------------------------------------------- The checksums below were generated using the "sum" and "md5sum" commands and are as follows: Filename sum md5 ===================================================================== IY67248_00.050128.epkg.Z 41289 4491 333bcc260883bbf50409f4874b6cb3a2 IY67248_01.050128.epkg.Z 60904 4420 38011246f7ddd4aefffa33b91633b13b These sums should match exactly. The PGP signatures in the compressed tarball and on this advisory can also be used to verify the integrity of the various files they correspond to. If the sums or signatures cannot be confirmed, double check the command results and the download site address. If those are OK, contact IBM AIX Security at security-alert@austin.ibm.com and describe the discrepancy. IMPORTANT: If possible, it is recommended that a mksysb backup of the system is created. Verify it is both bootable, and readable before proceeding. These efixes have not been fully regression tested; thus, IBM does not warrant the fully correct functioning of the efix. Customers install the efix and operate the modified version of AIX at their own risk. Efix Installation Instructions: -------------------------------- The efix package for AIX 5.3.0 with no maintenance level is named IY67248_01.050128.epkg.Z and the efix package for AIX 5.3.0 with maintenance level one installed is named IY67248_00.050128.epkg.Z. These packages use the new Emergency Fix Management Solution to install and manage efixes. More information can be found at: http://techsupport.services.ibm.com/server/aix.efixmgmt To preview an epkg efix installation execute the following command: # emgr -e epkg_name -p # where epkg_name is the name of the # efix package being previewed. To install an epkg efix package, execute the following command: # emgr -e epkg_name -X # where epkg_name is the name of the # efix package being installed. It is strongly recommended that this efix be mount installed before doing a regular install. A mount install will mount the patched binaries over existing system binaries. If any issues arise, the efix can be unmounted or the system can be rebooted to revert of the original system files. The mount an epkg efix package, execute the following command: # emgr -m epkg_name -X # where epkg_name is the name of the # efix package being installed. The "X" flag will expand any filesystems if required. C. Workaround The system file /etc/passwd contains the string "+::0:0:::" when the system is configured as a NIS client. To remove this vulnerability, that line should be changed to "+:". Note that this change can only be done by the root user. IV. Obtaining Fixes =================== AIX Version 5 APARs can be downloaded from: http://www-1.ibm.com/servers/eserver/support/pseries/aixfixes.html Security related Emergency Fixes can be downloaded from: ftp://aix.software.ibm.com/aix/efixes/security V. Contact Information ======================== If you would like to receive AIX Security Advisories via email, please visit: https://techsupport.services.ibm.com/server/pseries.subscriptionSvcs 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 send email to security-alert@austin.ibm.com with a subject of "get key". The key can also be downloaded from a PGP Public Key Server. The key id is 0x9391C1F2. 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. [***** End IBM Security Advisory Issued 1/30/2005 *****] _______________________________________________________________________________ CIAC wishes to acknowledge the contributions of IBM for the information contained in this bulletin. _______________________________________________________________________________ CIAC, the Computer Incident Advisory Capability, is the computer security incident response team for the U.S. Department of Energy (DOE) and the emergency backup response team for the National Institutes of Health (NIH). CIAC is located at the Lawrence Livermore National Laboratory in Livermore, California. CIAC is also a founding member of FIRST, the Forum of Incident Response and Security Teams, a global organization established to foster cooperation and coordination among computer security teams worldwide. CIAC services are available to DOE, DOE contractors, and the NIH. CIAC can be contacted at: Voice: +1 925-422-8193 (7x24) FAX: +1 925-423-8002 STU-III: +1 925-423-2604 E-mail: ciac@ciac.org Previous CIAC notices, anti-virus software, and other information are available from the CIAC Computer Security Archive. World Wide Web: http://www.ciac.org/ Anonymous FTP: ftp.ciac.org PLEASE NOTE: Many users outside of the DOE, ESnet, and NIH computing communities receive CIAC bulletins. If you are not part of these communities, please contact your agency's response team to report incidents. Your agency's team will coordinate with CIAC. The Forum of Incident Response and Security Teams (FIRST) is a world-wide organization. A list of FIRST member organizations and their constituencies can be obtained via WWW at http://www.first.org/. This document was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor the University of California nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial products, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation or favoring by the United States Government or the University of California. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or the University of California, and shall not be used for advertising or product endorsement purposes. LAST 10 CIAC BULLETINS ISSUED (Previous bulletins available from CIAC) P-108: libdbi-perl P-109: Cisco IOS Misformed BGP Packet Causes Reload P-110: Crafted Packet Causes Reload on Cisco Routers P-111: Cisco Multiple Crafted IPv6 Packets Cause Reload P-112: Updated less Package Fixes Security Issue P-113: BIND Vulnerabilities P-114: BIND: Self Check Failing P-115: libpam-radius-auth P-116: Apple Security Update for Mac OS X P-117: UW-imapd Fails to Properly Authenticate Users When Using CRAM-MD5