-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 =============================================================================== >> CERT-NL, 01-Mar-2000 << >> All CERT-NL information has been moved to http://cert.surfnet.nl. Links << >> to CERT-NL information contained in this advisory are therefore outdated. << >> << >> CERT-NL also has stopped the CERT-CC-Mirror service. Due to this the << >> links to the CERT-CC mirror are obsolete. Visit the CERT-CC site for the << >> complete CERT-CC advisory texts: http://www.cert.org << =============================================================================== =============================================================================== Security Advisory CERT-NL =============================================================================== Author/Source : Rene Ritzen Index : S-98-16 Distribution : World Page : 1 Classification: External Version: 1 Subject : SGI Vulnerability in suidperl/sperl program Date : 14-Apr-98 =============================================================================== By courtesy of Silicon Graphics, Inc. we received information on a Buffer Overflow Vulnerability in suidperl/sperl program CERT-NL recommends to perform the workaround outlined in the section temporary solution below. ============================================================================== ______________________________________________________________________________ Silicon Graphics Inc. Security Advisory Title: Buffer Overflow Vulnerability in suidperl/sperl program Title: CERT CA-97.17 and AUSCERT AA-97.13 Number: 19980404-01-I Date: April 6, 1998 ______________________________________________________________________________ Silicon Graphics provides this information freely to the SGI user community for its consideration, interpretation, implementation and use. Silicon Graphics recommends that this information be acted upon as soon as possible. Silicon Graphics provides the information in this Security Advisory on an "AS-IS" basis only, and disclaims all warranties with respect thereto, express, implied or otherwise, including, without limitation, any warranty of merchantability or fitness for a particular purpose. In no event shall Silicon Graphics be liable for any loss of profits, loss of business, loss of data or for any indirect, special, exemplary, incidental or consequential damages of any kind arising from your use of, failure to use or improper use of any of the instructions or information in this Security Advisory. ______________________________________________________________________________ - - - - ----------------------- - - - - --- Issue Specifics --- - - - - ----------------------- The suidperl or sperl program is an altered versions of PERL which allows PERL scripts to be run under the setuid of a particular user. Unfortunately, a buffer overrun has been discovered in the suidperl/sperl program which could allow arbitrary commands to be run as the privileged user root. Silicon Graphics Inc. has investigated the issue and recommends the following steps for neutralizing the exposure. It is HIGHLY RECOMMENDED that these measures be implemented on ALL vulnerable SGI systems. - - - - -------------- - - - - --- Impact --- - - - - -------------- As a service to its customers, Silicon Graphics provides IRIX installable inst images of many popular "free" software packages and can be found on the SGI Freeware 1.0/2.0 CD or online at: http://www.sgi.com/TasteOfDT/public/freeware.html The suidperl/sperl program is freeware and is not installed by default. Versions 5.003 and lower of suidperl/sperl have this buffer overrun vulnerability. With a local account, the suidperl/sperl buffer overrun vulnerability can be exploited locally and remotely. The suidperl/sperl buffer overrun vulnerability can be utilized to execute commands with root privileges. The suidperl/sperl buffer overrun vulnerability has been publicly discussed in Usenet newsgroups and mailing lists and also reported in CERT Advisory CA-97.17 and AUSCERT Advisory AA-97.13. - - - - -------------------------- - - - - --- Temporary Solution --- - - - - -------------------------- Although new releases of suidperl/sperl are available to fix this issue, it is realized that there may be situations where installing the new release immediately may not be possible. To determine if a system is vulnerable to this problem and to disable the programs that are believed to be vulnerable, use the following steps. 1) Become the root user on the system. % /bin/su - Password: # 2) Find suidperl or sperl programs and disable them. You will need to run the find(1) command on each system you maintain because the command examines files on local disks only. Note that this is one long command, though we have separated it onto five lines using backslashes. # find / -local -type f -user root \ \( -name 'sperl4.[0-9][0-9][0-9]' \ -o -name 'sperl5.00[0-3]' \ -o -name 'suidperl' \) \ -perm -04000 -print -ok chmod ug-s '{}' \; This command will find all files on a system that are - only in the file system you name (/ -local) - regular files (-type f) - owned by root (-user root) - named appropriately (-name 'sperl4.[0-9][0-9][0-9]' -o -name 'sperl5.00[0-3]' -o -name 'suidperl') - setuid root (-perm -04000) Once found, those files will - have their names printed (-print) - have their modes changed, but only if you type `y' in response to the prompt (-ok chmod ug-s '{}' \;) After you have run this command on all your systems, they will no longer be vulnerable. Note that after disabling the suidperl and sperl programs, they will no longer be able to emulate the set-user-ID and set-group-ID features of the kernel. 3) Return to previous level. # exit $ - - - - ---------------- - - - - --- Solution --- - - - - ---------------- No Silicon Graphic's patches are available for freeware software. As freeware software, all reasonable efforts will be made to address the issue in future releases of the Silicon Graphic's Freeware. Unsupported patches are publicly available from http://www.perl.com/ - - - - ------------------------ - - - - --- Acknowledgments --- - - - - ------------------------ Silicon Graphics wishes to thank the Internet Community, CERT Coordination Center, and AUSCERT for their assistance in this matter. - - - - ----------------------------------------------------------- - - - - --- Silicon Graphics Inc. Security Information/Contacts --- - - - - ----------------------------------------------------------- If there are questions about this document, email can be sent to cse-security-alert@sgi.com. ============================================================================== CERT-NL is the Computer Emergency Response Team for SURFnet customers. SURFnet is the Dutch network for educational, research and related institutes. CERT-NL is a member of the Forum of Incident Response and Security Teams (FIRST). All CERT-NL material is available under: http://cert.surfnet.nl/ In case of computer or network security problems please contact your local CERT/security-team or CERT-NL (if your institute is NOT a SURFnet customer please address the appropriate (local) CERT/security-team). CERT-NL is one/two hour(s) ahead of UTC (GMT) in winter/summer, i.e. UTC+0100 in winter and UTC+0200 in summer (DST). 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