-----BEGIN PGP SIGNED MESSAGE----- ****************** FOR PUBLIC RELEASE ******************** __________________________________________________________ The U.S. Department of Energy Computer Incident Advisory Capability ___ __ __ _ ___ / | /_\ / \___ __|__ / \ \___ __________________________________________________________ INFORMATION BULLETIN SGI IRIX xlock Vulnerability July 8, 1997 18:00 GMT Number H-80 ______________________________________________________________________________ PROBLEM: A problem has been identified in SGI IRIX xlock program. PLATFORM: All SGI systems running IRIX. DAMAGE: This vulnerability may be utilized to execute commands with root privileges. SOLUTION: Follow SGI's recommended steps to neutralize exposure. ______________________________________________________________________________ VULNERABILITY It is HIGHLY RECOMMENDED that these steps be implemented on all ASSESSMENT: SGI systems. ______________________________________________________________________________ [ Start SGI Advisories ] - -----BEGIN PGP SIGNED MESSAGE----- ______________________________________________________________________________ Silicon Graphics Inc. Security Advisory Title: xlock Vulnerability Number: 19970502-02-PX Date: July 7, 1997 ______________________________________________________________________________ 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 xlock(1) program is used to lock the local X display of a system until a correct password is entered at the keyboard. The program is setuid root and as part of the process of locking an X display accepts user arguments to establish specific xlock operation. It has been determined that an appropriately crafted set of arguments could be input to the xlock program allowing execution of arbitrary user commands with root privileges. This resulting buffer overflow condition is considered a security vulnerability in the xlock program. 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 SGI systems. This issue will be corrected in future releases of IRIX. - --------------- - ---- Impact --- - --------------- The xlock program (/usr/bin/X11/xlock) is installed on all IRIX systems by default. A local account is required in order to exploit this vulnerability both locally and remotely. This vulnerability can be utilized to execute commands with root privileges. This vulnerability has been publically discussed and reported in CERT advisory CA-97.13 and AUSCERT advisory AA-97.24. - --------------------------- - ---- Temporary Solution --- - --------------------------- Although patches are available for this issue, it is realized that there may be situations where installing the patches immediately may not be possible. The steps below can be used to remove the vulnerability by removing the permissions of the xlock program. 1) Become the root user on the system. % /bin/su - Password: # 2) Change the permissions on the xlock program. # /bin/chmod 500 /usr/bin/X11/xlock ************ *** NOTE *** ************ Removing the setuid root permissions from the xlock program will prevent non-root users from using the xlock to lock their terminal. 3) Return to previous level. # exit $ - ----------------- - ---- Solution --- - ----------------- OS Version Vulnerable? Patch # Other Actions ---------- ----------- ------- ------------- IRIX 3.x no IRIX 4.x no IRIX 5.0.x yes not avail Note 1 IRIX 5.1.x yes not avail Note 1 IRIX 5.2 yes not avail Note 1 IRIX 5.3 yes 2090 IRIX 6.0.x yes not avail Note 1 IRIX 6.1 yes not avail Note 1 IRIX 6.2 yes 2090 IRIX 6.3 yes 2090 IRIX 6.4 yes 2091 NOTES 1) upgrade operating system or see "Temporary Solution" section. Patches are available via anonymous FTP and your service/support provider. The SGI anonymous FTP site is sgigate.sgi.com (204.94.209.1) or its mirror, ftp.sgi.com. Security information and patches can be found in the ~ftp/security and ~ftp/patches directories, respectfully. ##### Patch File Checksums #### The actual patch will be a tar file containing the following files: Filename: README.patch.2090 Algorithm #1 (sum -r): 50124 8 README.patch.2090 Algorithm #2 (sum): 49453 8 README.patch.2090 MD5 checksum: 4D51EA09250113215760C045BE8F5E14 Filename: patchSG0002090 Algorithm #1 (sum -r): 49562 1 patchSG0002090 Algorithm #2 (sum): 25201 1 patchSG0002090 MD5 checksum: 99F72D8E24773A63306A0118F56411E7 Filename: patchSG0002090.idb Algorithm #1 (sum -r): 47573 1 patchSG0002090.idb Algorithm #2 (sum): 35831 1 patchSG0002090.idb MD5 checksum: 9E16916C33EA81D2C090A9162FB7B099 Filename: patchSG0002090.x_eoe_sw Algorithm #1 (sum -r): 40887 114 patchSG0002090.x_eoe_sw Algorithm #2 (sum): 62640 114 patchSG0002090.x_eoe_sw MD5 checksum: 7088ECF05104E049DCC1D5150EE41F8C Filename: README.patch.2091 Algorithm #1 (sum -r): 08547 8 README.patch.2091 Algorithm #2 (sum): 35395 8 README.patch.2091 MD5 checksum: 54836F64E12DDBAE09E1F165B42A7B01 Filename: patchSG0002091 Algorithm #1 (sum -r): 50655 1 patchSG0002091 Algorithm #2 (sum): 27369 1 patchSG0002091 MD5 checksum: 857AE0806FE273DB75F99264873828FD Filename: patchSG0002091.idb Algorithm #1 (sum -r): 07183 1 patchSG0002091.idb Algorithm #2 (sum): 35505 1 patchSG0002091.idb MD5 checksum: 134D7A6DC774425B6CC73A84A9468833 Filename: patchSG0002091.x_eoe_sw Algorithm #1 (sum -r): 23378 102 patchSG0002091.x_eoe_sw Algorithm #2 (sum): 26001 102 patchSG0002091.x_eoe_sw MD5 checksum: 1FF45DAC2F7FDCCAB8A982ED77554DDA - ------------------------- - ---- Acknowledgments --- - ------------------------- Silicon Graphics Inc. wishes to thank the CERT Coordination Center and AUSCERT for their assistance in this issue. - ------------------------------------------------------------ - ---- Silicon Graphics Inc. Security Information/Contacts --- - ------------------------------------------------------------ If there are questions about this document, email can be sent to cse-security-alert@sgi.com. ------oOo------ Silicon Graphics provides security information and patches for use by the entire SGI community. This information is freely available to any person needing the information and is available via anonymous FTP and the Web. The primary SGI anonymous FTP site for security information and patches is sgigate.sgi.com (204.94.209.1). Security information and patches are located under the directories ~ftp/security and ~ftp/patches, respectively. The Silicon Graphics Security Headquarters Web page is accessible at the URL http://www.sgi.com/Support/Secur/security.html. For issues with the patches on the FTP sites, email can be sent to cse-security-alert@sgi.com. For assistance obtaining or working with security patches, please contact your SGI support provider. ------oOo------ Silicon Graphics provides a free security mailing list service called wiretap and encourages interested parties to self-subscribe to receive (via email) all SGI Security Advisories when they are released. Subscribing to the mailing list can be done via the Web (http://www.sgi.com/Support/Secur/wiretap.html) or by sending email to SGI as outlined below. % mail wiretap-request@sgi.com subscribe wiretap end ^d In the example above, is the email address that you wish the mailing list information sent to. The word end must be on a separate line to indicate the end of the body of the message. The control-d (^d) is used to indicate to the mail program that you are finished composing the mail message. ------oOo------ Silicon Graphics provides a comprehensive customer World Wide Web site. This site is located at http://www.sgi.com/Support/Secur/security.html. ------oOo------ For reporting *NEW* SGI security issues, email can be sent to security-alert@sgi.com or contact your SGI support provider. A support contract is not required for submitting a security report. ______________________________________________________________________________ This information is provided freely to all interested parties and may be redistributed provided that it is not altered in any way, Silicon Graphics is appropriately credited and the document retains and includes its valid PGP signature. - -----BEGIN PGP SIGNATURE----- Version: 2.6.2 iQCVAwUBM8FvdLQ4cFApAP75AQFUeQQAkSGeKlM8xVnrnkxffodmCYKm5DP5SGCU mfRiIvi9i2tuuzOGNNDGo7d5DE2xhL+40yfoNUTNBvCpj5Oz5KHUyWU93kfQGB3c f3JgsEcc8s888cOqTRenqhqP6Ey0+tjJItsRC5oo+hharJTAcmTBh9BRBHm5I5UL ngmPNnHE3pE= =rLt0 - -----END PGP SIGNATURE----- [ End SGI Advisories ] _______________________________________________________________________________ CIAC wishes to acknowledge the contributions of Silicon Graphics Inc. 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: +1 510-422-8193 FAX: +1 510-423-8002 STU-III: +1 510-423-2604 E-mail: ciac@llnl.gov For emergencies and off-hour assistance, DOE, DOE contractor sites, and the NIH may contact CIAC 24-hours a day. During off hours (5PM - 8AM PST), call the CIAC voice number 510-422-8193 and leave a message, or call 800-759-7243 (800-SKY-PAGE) to send a Sky Page. CIAC has two Sky Page PIN numbers, the primary PIN number, 8550070, is for the CIAC duty person, and the secondary PIN number, 8550074 is for the CIAC Project Leader. Previous CIAC notices, anti-virus software, and other information are available from the CIAC Computer Security Archive. World Wide Web: http://ciac.llnl.gov/ Anonymous FTP: ciac.llnl.gov (198.128.39.53) Modem access: +1 (510) 423-4753 (28.8K baud) +1 (510) 423-3331 (28.8K baud) 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 Majordomo, which ignores E-mail header subject lines. To subscribe (add yourself) to one of our mailing lists, send the following request as the E-mail message body, substituting ciac-bulletin, ciac-notes, spi-announce OR spi-notes for list-name: E-mail to ciac-listproc@llnl.gov or majordomo@tholia.llnl.gov: subscribe list-name e.g., subscribe ciac-notes You will receive an acknowledgment email immediately with a confirmation that you will need to mail back to the addresses above, as per the instructions in the email. This is a partial protection to make sure you are really the one who asked to be signed up for the list in question. If you include the word 'help' in the body of an email to the above address, it will also send back an information file on how to subscribe/unsubscribe, get past issues of CIAC bulletins via email, etc. 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. 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