From agent99@boytoy.csd.sgi.com Wed Jul 23 15:37:50 1997 Date: Wed, 23 Jul 1997 14:13:58 -0700 From: SGI Security Coordinator To: agent99@sgi.com Subject: SGI Security Advisory 19970701-01-PX - talkd Vulnerability DISTRIBUTION RESTRICTIONS - NONE - FOR PUBLIC RELEASE -----BEGIN PGP SIGNED MESSAGE----- ______________________________________________________________________________ Silicon Graphics Inc. Security Advisory Title: talkd Vulnerability Number: 19970701-01-PX Date: July 23, 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 talkd(8) program is a support program for the user to user communications program talk(1). As part of the start of talk communications between two users, the talkd program obtains network hostname information from DNS and then coordinates notifying users of a requested talk session. A security vulnerability has been discovered in which manipulation of provided network hostname information to the talkd program can be used to execute arbitrary commands with root privileges. 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 talkd program (/usr/etc/talkd) is installed on all IRIX systems by default. For this particular vulnerability, a local account is not required. Furthermore, the vulnerability can be exploited remotely. This vulnerability can be utilized to execute commands with root privileges. This vulnerability has been public-ally discussed and reported in AUSCERT advisory AA-97.01 and CERT advisory CA-97.04. - -------------------------- - --- 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 disabling the talkd program. 1) Become the root user on the system. % /bin/su - Password: # 2) Edit the file /etc/inetd.conf . Place a "#" as the first character of the talkd line to comment out and deactivate the service. # vi /usr/etc/inetd.conf {Find the following line} ntalk dgram udp wait root /usr/etc/talkd talkd {Place a "#" as the first character of the ntalk line} #ntalk dgram udp wait root /usr/etc/talkd talkd {Save the file and exit} 3) Force inetd to re-read the configuration file. # /etc/killall -HUP inetd 4) Return to previous level. # exit $ - ---------------- - --- Solution --- - ---------------- OS Version Vulnerable? Patch # Other Actions ---------- ----------- ------- ------------- IRIX 3.x yes not avail Note 1 IRIX 4.x yes not avail Note 1 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 2132 IRIX 6.0.x yes not avail Note 1 IRIX 6.1 yes not avail Note 1 IRIX 6.2 yes 2133 IRIX 6.3 yes 2133 IRIX 6.4 yes 2133 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.2132 Algorithm #1 (sum -r): 58795 8 README.patch.2132 Algorithm #2 (sum): 22126 8 README.patch.2132 MD5 checksum: 1C16F01A682CC8DB605DEC4C515B3ADD Filename: patchSG0002132 Algorithm #1 (sum -r): 39922 1 patchSG0002132 Algorithm #2 (sum): 24988 1 patchSG0002132 MD5 checksum: 1BD1683D23D164F954BEE893B3CF8B2F Filename: patchSG0002132.eoe2_sw Algorithm #1 (sum -r): 29839 26 patchSG0002132.eoe2_sw Algorithm #2 (sum): 636 26 patchSG0002132.eoe2_sw MD5 checksum: EDB8C15F7D22F7104770D591952346E7 Filename: patchSG0002132.idb Algorithm #1 (sum -r): 54227 1 patchSG0002132.idb Algorithm #2 (sum): 34895 1 patchSG0002132.idb MD5 checksum: 82E411637E20CB15E9EEFA3BA330F93D Filename: README.patch.2133 Algorithm #1 (sum -r): 53634 8 README.patch.2133 Algorithm #2 (sum): 26859 8 README.patch.2133 MD5 checksum: 20FE236BEAC79EC8614BE84B5E291841 Filename: patchSG0002133 Algorithm #1 (sum -r): 05188 1 patchSG0002133 Algorithm #2 (sum): 27188 1 patchSG0002133 MD5 checksum: A4E881E9682DA41DE8897DE71D2EE42C Filename: patchSG0002133.eoe_sw Algorithm #1 (sum -r): 24652 27 patchSG0002133.eoe_sw Algorithm #2 (sum): 6068 27 patchSG0002133.eoe_sw MD5 checksum: 7ECC472AFE5105D195BCC2B75834D666 Filename: patchSG0002133.idb Algorithm #1 (sum -r): 45369 1 patchSG0002133.idb Algorithm #2 (sum): 35211 1 patchSG0002133.idb MD5 checksum: 5BE2481FB3F325399BEE961AF0FB476C - ------------------------ - --- 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/security. For issues with the patches on the FTP sites, email can be sent to cse-security-alert@sgi.com. 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This site is located at http://www.sgi.com/Support/security. ------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 iQCVAwUBM9Y9v7Q4cFApAP75AQG1PgP+OV1lJX8FOpH2Np6dF8GBymnB6EemhDex O4R1m1TxjuBapWNTjIFcdCHKygnto/9Mq0oAmS7LoHfEz3+LZN/d/2uJwTJRvlV+ ttSgiVNIbP+jyiiVnhSV7U+IWtUNBBqgDCfQIxRjgmWnuIr9BjVRQfC4szDXQkXd 5PApltoJERo= =o3DO -----END PGP SIGNATURE-----