CERT Vendor-Initiated Bulletin VB-95:02 March 8, 1995 Topic: IRIX 5.2, 6.0, 6.0.1 Desktop Permissions Tool Source: Silicon Graphics Inc. To aid in the wide distribution of essential security information, the CERT Coordination Center is forwarding the following information from Silicon Graphics Inc. (SGI). SGI urges you to act on this information as soon as possible. SGI contact information is included in the forwarded text below; please contact them if you have any questions or need further information. ========================FORWARDED TEXT STARTS HERE============================ _______________________________________________________________________________ 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. 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