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ESB-98.167 -- IBM-ERS Security Vulnerability Alert #1998:004.1 -- AIX automountd Vulnerability
27 October 1998
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-----BEGIN PGP SIGNED MESSAGE----- =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-98.167 -- IBM-ERS Security Vulnerability Alert #1998:004.1 AIX automountd Vulnerability 27 October 1998 =========================================================================== The IBM Emergency Response Service has released the following alert concerning a vulnerability in the automountd daemon in IBM AIX(r) 4.3.x. This vulnerability may allow local and remote users to gain root access. - ---------------------------BEGIN INCLUDED TEXT-------------------- - -----BEGIN PGP SIGNED MESSAGE----- - - --ERS-ALERT--ERS-ALERT--ERS-ALERT--ERS-ALERT--ERS-ALERT--ERS-ALERT--ERS-ALERT-- - - ---EXTERNAL RELEASE---EXTERNAL RELEASE---EXTERNAL RELEASE---EXTERNAL RELEASE--- ======= ============ ====== ====== ======= ============== ======= ======= === === ==== ====== ====== === =========== ======= ======= === =========== === ======= === === === ==== === ===== === ======= ============== ===== === ===== ======= ============ ===== = ===== EMERGENCY RESPONSE SERVICE SECURITY VULNERABILITY ALERT 26 October 1998 14:00 GMT Number: ERS-SVA-E01-1998:004.1 =============================================================================== VULNERABILITY SUMMARY VULNERABILITY: The automountd daemon allows local and remote users to become root. PLATFORMS: IBM AIX(r) 4.3.x SOLUTION: Apply the fixes listed below. THREAT: Remote users can execute arbitrary commands as root. =============================================================================== DETAILED INFORMATION I. Description The automountd daemon processes requests from the local AutoFS filesystem kernel extension. It uses local files or name service maps to locate file systems to be mounted. Because the daemon does not verify that requests are actually from the kernel extension, local non-root users and remote users can request automountd services. II. Impact If the automountd daemon is active, local and remote users can cause arbitrary commands to run as root. Exploits for this problem have been made publicly available. To determine if the daemon is active on your system, run the following command: $ lssrc -s automountd To disable the daemon until the fix can be applied (run as root): # stopsrc -s automountd III. Solutions A. Official fix IBM is working on the following fixes which will be available soon. AIX 4.1.x: not vulnerable AIX 4.2.x: not vulnerable AIX 4.3.x: IX83752 B. How to alleviate the problem A temporary fix is available via anonymous ftp from: ftp://aix.software.ibm.com/aix/efixes/security/automountd.tar.Z Filename sum md5 ================================================================== autofs.ext 26103 117 4afedf8fbe411e8be2588fa8843211ae automountd 16386 83 eb4c2e1c4cfe609b2ecba0c6a704640c NOTE - This temporary fix has not been fully regression tested. Use the following steps (as root) to install the temporary fix: 1. Determine the version of the NFS fileset on your machine. # lslpp -l bos.net.nfs.client The version of the fileset for your machine should be at 126.96.36.199 or higher. If not, install requisite APAR IX81896. This will help ensure that the temporary fix will run properly. 2. Uncompress and extract the fix. # uncompress < automountd.tar.Z | tar xf - # cd automountd 3. Replace the vulnerable executables with the temporary fix. # (cd /usr/lib/drivers && mv autofs.ext autofs.ext.before_security_fix) # (cd /usr/sbin && mv automountd automountd.before_security_fix) # chmod 0 /usr/lib/drivers/autofs.ext.before_security_fix # chmod 0 /usr/sbin/automountd.before_security_fix # cp ./autofs.ext /usr/lib/drivers/autofs.ext # cp ./automountd /usr/sbin/automountd # chown root.system /usr/sbin/automountd /usr/lib/drivers/autofs.ext # chmod 555 /usr/sbin/automountd /usr/lib/drivers/autofs.ext 4. Reboot. IV. Obtaining Fixes IBM AIX APARs may be ordered using Electronic Fix Distribution (via the FixDist program), or from the IBM Support Center. For more information on FixDist, and to obtain fixes via the Internet, please reference http://aix.software.ibm.com/support/rs6000 or send email to "firstname.lastname@example.org" with the word "FixDist" in the "Subject:" line. To facilitate ease of ordering all security related APARs for each AIX release, security fixes are periodically bundled into a cumulative APAR. For more information on these cumulative APARs including last update and list of individual fixes, send email to "email@example.com" with the word "subscribe Security_APARs" in the "Subject:" line. V. Acknowledgements Thanks to Repent Security Incorporated for bringing this problem to our attention. A copy of their autofsd advisory can be found at http://www.repsec.com/. VI. Contact Information Comments regarding the content of this announcement can be directed to your local IBM support center or to: firstname.lastname@example.org To request the PGP public key that can be used to encrypt new AIX security vulnerabilities, send email to email@example.com with a subject of "get key". If you would like to subscribe to the AIX security newsletter, send a note to firstname.lastname@example.org with a subject of "subscribe Security". To cancel your subscription, use a subject of "unsubscribe Security". To see a list of other available subscriptions, use a subject of "help". IBM and AIX are a registered trademark of International Business Machines Corporation. All other trademarks are property of their respective holders. =============================================================================== IBM's Internet Emergency Response Service (IBM-ERS) is a subscription-based Internet security response service that includes computer security incident response and management, regular electronic verification of your Internet gateway(s), and security vulnerability alerts similar to this one that are tailored to your specific computing environment. By acting as an extension of your own internal security staff, IBM-ERS's team of Internet security experts helps you quickly detect and respond to attacks and exposures across your Internet connection(s). As a part of IBM's Business Recovery Services organization, the IBM Internet Emergency Response Service is a component of IBM's SecureWay(tm) line of security products and services. From hardware to software to consulting, SecureWay solutions can give you the assurance and expertise you need to protect your valuable business resources. To find out more about the IBM Internet Emergency Response Service, send an electronic mail message to email@example.com, or call 1-800-742-2493 (Prompt 4). IBM-ERS maintains a site on the World Wide Web at http://www.ers.ibm.com/. Visit the site for information about the service, copies of security alerts, team contact information, and other items. IBM-ERS uses Pretty Good Privacy* (PGP*) as the digital signature mechanism for security vulnerability alerts and other distributed information. The IBM-ERS PGP* public key is available from http://www.ers.ibm.com/team-info/pgpkey.html. "Pretty Good Privacy" and "PGP" are trademarks of Philip Zimmermann. IBM-ERS is a Member Team of the Forum of Incident Response and Security Teams (FIRST), a global organization established to foster cooperation and response coordination among computer security teams worldwide. Copyright 1998 International Business Machines Corporation. The information in this document is provided as a service to customers of the IBM Emergency Response Service. Neither International Business Machines Corporation, nor any of its employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, complete- ness, or usefulness of any information, apparatus, product, or process contained herein, or represents that its use would not infringe any 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 IBM or its subsidiaries. The views and opinions of authors expressed herein do not necessarily state or reflect those of IBM or its subsidiaries, and may not be used for advertising or product endorsement purposes. The material in this security alert may be reproduced and distributed, without permission, in whole or in part, by other security incident response teams (both commercial and non-commercial), provided the above copyright is kept intact and due credit is given to IBM-ERS. This security alert may be reproduced and distributed, without permission, in its entirety only, by any person provided such reproduction and/or distribution is performed for non-commercial purposes and with the intent of increasing the awareness of the Internet community. - - ---EXTERNAL RELEASE---EXTERNAL RELEASE---EXTERNAL RELEASE---EXTERNAL RELEASE--- - - --ERS-ALERT--ERS-ALERT--ERS-ALERT--ERS-ALERT--ERS-ALERT--ERS-ALERT--ERS-ALERT-- - -----BEGIN PGP SIGNATURE----- Version: 2.7.1 iQCVAwUBNjSC6/WDLGpfj4rlAQHuLQP+NdsdYnwg9Ps9FdOR2AbRgidBWHD2Bisa uzMV1mpoWh99+Dj+EJMhKZ5kEF9QU+9t01mVU3akJoWfWzkbpd/cVONkiFY0XYHf wOw3t7s1NPVK1qZBbAG+ADVhmtjpOtnLgbKtCF1Pfay8vIh8kY+5cTGa+nyrNFRv fhcCSeluFHo= =YJXl - -----END PGP SIGNATURE----- - ---------------------------END INCLUDED TEXT-------------------- 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 use any or all of this information is the responsibility of each user or organisation, and should be done so in accordance with site policies and procedures. NOTE: This is only the original release of the security bulletin. It will 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 original authors 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/Information/advisories.html If you believe that your system has been compromised, contact AusCERT or your representative in FIRST (Forum of Incident Response and Security Teams). Internet Email: firstname.lastname@example.org 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 emergencies. -----BEGIN PGP SIGNATURE----- Version: 2.6.3i Charset: noconv Comment: ftp://ftp.auscert.org.au/pub/auscert/AUSCERT_PGP.key iQCVAwUBNkLIhyh9+71yA2DNAQEgrwP/eKXkUuN1Zo6POa/CmE9fevVPzyB4XL+S R2KqQvd5rT5GiXBWSSxlPB1cTnD72Ua8NdpH6uDc1Q7T2UA++mY6NSeSLJhZaWVr jOvkHXH/IjPOgVhlgmM9ezODA7l63ztBWZ1YElMsOA0anPSM3bhtoUnQF76NB9eu txpUpXlZVX0= =fM6F -----END PGP SIGNATURE-----
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