_____________________________________________________ The U.S. Department of Energy Computer Incident Advisory Capability ___ __ __ _ ___ / | /_\ / \___ __|__ / \ \___ _____________________________________________________ INFORMATION BULLETIN SGI IRIX Desktop Permissions Tool Vulnerability March 8, 1995 1500 PST Number F-16 _____________________________________________________________________________ PROBLEM: A vulnerability exists in /usr/lib/desktop/permissions. PLATFORM: SGI IRIX Version 5.2, 6.0, 6.0.1 DAMAGE: Local users can change the permissions of any file. SOLUTION: Change the permissions on /usr/lib/desktop/permissions or install the SGI security patch patchSG0000373. _____________________________________________________________________________ VULNERABILITY An exploitation script for this vulnerability has been widely ASSESSMENT: distributed on the Internet. Affected sites should change permissions or install this fix as soon as possible. _____________________________________________________________________________ Critical Information about IRIX Permissions Tool CIAC has received information about a vulnerability in the Silicon Graphics IRIX operating system. The file /usr/lib/desktop/permissions contains a vulnerability which can allow local users to change permissions of any file and gain root access to the system. Following is SGI bulletin 19950301-01-P373. _______________________________________________________________________________ Silicon Graphics Inc. Security Advisory Title: IRIX 5.2, 6.0, 6.0.1 Desktop Permissions Tool Number: 19950301-01-P373 Date: March 3, 1995 _______________________________________________________________________________ Silicon Graphics provides this information freely to the SGI community for its consideration, interpretation and implementation. Silicon Graphics recommends that this information be acted upon as soon as possible. Silicon Graphics will not be liable for any consequential damages arising from the use of, or failure to use or use properly, any of the instructions or information in this Security Advisory. _______________________________________________________________________________ A vulnerability has been discovered in the IRIX 5.2, 6.0, and 6.0.1 operating systems regarding the permissions tool under the IRIX desktop environment. Normally, this tool is used by users to modify the permissions on their files and files they are privileged for. Under certain conditions, a user may be able to modify the permissions for any file. This is identified as SGI SCR # 265071. SGI Engineering has investigated this issue and recommends the following steps for neutralizing the exposure. It is HIGHLY RECOMMENDED that these measures be done on ALL SGI systems running IRIX 5.2, 6.0, and 6.0.1 . This issue is corrected in 5.3 of IRIX and will be corrected in future releases of IRIX. - -------------------------- - --- Immediate Solution --- - -------------------------- The most immediate solution for this issue is to remove the setuid/setgid bits on /usr/lib/permissions, or to remove the tool entirely. Removing the setuid/setgid bits will limit the tool to only function on files owned by the user using the tool. 1) Become the root user on the system. % /bin/su - Password: # 2) Change the unix permissions level on the desktop permissions program. # chmod u-s /usr/lib/desktop/permissions # chmod g-s /usr/lib/desktop/permissions 3) Return to previous user. # exit % - -------------------------- - --- Long Term Solution --- - -------------------------- *** IRIX 5.0.x, 5.1.x **** The versions 5.0.x and 5.1.x of IRIX were limited hardware, specific releases and have since been obsoleted by later versions of IRIX. For supportability reasons, upgrading to at least IRIX 5.2 is recommended as a first step for all problem resolution. IRIX 5.0.x, 5.1.x ARE NOT subject to this vulnerability. **** IRIX 5.2, 6.0, 6.0.1 **** >>>> IRIX 5.3 IS NOT SUBJECT TO THIS VULNERABILITY. <<<< For the IRIX operating system versions 5.2, 6.0 and 6.0.1, an inst-able patch has been generated and made available via anonymous ftp and/or your service/support provider. The patch is number 373 and will install on IRIX 5.2, 6.0 and 6.0.1 . - -NOTE- Inst-able patches require a patch-aware inst program. The stock 5.2 inst program with the base install is not patch-aware. The 6.0 and 6.0.1 inst programs are. A patch-aware inst program for IRIX 5.2 is available as patch number 0, 34, or 84. Any one of these may be used, with 84 the latest, most recommended, and available via your service provider or the usual SGI anonymous ftp sites. The SGI anonymous ftp site is ftp.sgi.com (192.48.153.1). Additionally, the alternative SGI anonymous ftp site, sgigate.sgi.com, can be accessed to find the same files. On each of these servers, patch 373 can be found in the following directories: ~ftp/Security or ~ftp/Patches/5.2 ~ftp/Patches/6.0 ~ftp/Patches/6.0.1 ##### Checksums #### The actual patch will be a tar file containing the following files: Filename: patchSG0000373 Algorithm #1 (sum -r): 51249 1 patchSG0000373 Algorithm #2 (sum): 21641 1 patchSG0000373 MD5 checksum: 40A604013A05C2521152ED4B51C5D9A5 Filename: patchSG0000373.desktop_eoe_sw Algorithm #1 (sum -r): 09134 88 patchSG0000373.desktop_eoe_sw Algorithm #2 (sum): 63013 88 patchSG0000373.desktop_eoe_sw MD5 checksum: D74F9BDED3D51E9D28666CADF1B31945 Filename: patchSG0000373.idb Algorithm #1 (sum -r): 50435 1 patchSG0000373.idb Algorithm #2 (sum): 41363 1 patchSG0000373.idb MD5 checksum: 790E9A47909BC32D8E9FCE14EA4077D8 - ------------------------------------ - --- Further Information/Contacts --- - ------------------------------------ For obtaining security information, patches or assistance, please contact your SGI support provider. If there are questions about this document, email can be sent to cse-security-alert@csd.sgi.com . For reporting *NEW* SGI security issues, email can be sent to security-alert@sgi.com . ----------------------------------------------------------------------------- [End of SGI Bulletin] _____________________________________________________________________________ CIAC wishes to thank Silicon Graphics, Inc. and the Forum of Incident Response and Security Teams (FIRST) for their quick response to this problem. _____________________________________________________________________________ CIAC is the computer security incident response team for the U.S. Department of Energy. Services are available free of charge to DOE and DOE contractors. Voice: 510-422-8193 FAX: 510-423-8002 STU-III: 510-423-2604 E-mail: ciac@llnl.gov Previous CIAC Bulletins, anti-virus software, and other information are available via anonymous FTP from ciac.llnl.gov (IP address 128.115.19.53). CIAC has several self-subscribing mailing lists for electronic publications: 1. CIAC-BULLETIN for Advisories, highest priority - time critical information, and Bulletins, important computer security information; 2. CIAC-NOTES for Notes, a collection of computer security articles; 3. SPI-ANNOUNCE for official news about Security Profile Inspector (SPI) software updates, new features, distribution and availability; 4. SPI-NOTES, for discussion of problems and solutions regarding the use of SPI products. Our mailing lists are managed by a public domain software package called ListProcessor, which ignores E-mail header subject lines. To subscribe (add yourself) to one of our mailing lists, send requests of the following form: subscribe list-name LastName, FirstName PhoneNumber as the E-mail message body, substituting CIAC-BULLETIN, CIAC-NOTES, SPI-ANNOUNCE or SPI-NOTES for "list-name" and valid information for "LastName" "FirstName" and "PhoneNumber." Send to: ciac-listproc@llnl.gov not to: ciac@llnl.gov e.g., subscribe ciac-notes O'Hara, Scarlett 404-555-1212 x36 subscribe ciac-bulletin O'Hara, Scarlett 404-555-1212 x36 You will receive an acknowledgment containing address, initial PIN, and information on how to change either of them, cancel your subscription, or get help. _____________________________________________________________________________ PLEASE NOTE: Many users outside of the DOE and ESnet 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 by sending E-mail to first-request@first.org with an empty subject line and a message body containing the line: send first-contacts. 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, expressed or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, 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 nor the University of California, and shall not be used for advertising or product endorsement purposes.