From agent99@sgi.com Mon Jan 28 16:45:06 2002 From: SGI Security Coordinator To: agent99@sgi.com Date: Mon, 28 Jan 2002 10:46:24 -0800 (PST) Subject: [VulnWatch] IRIX O2 video security issue -----BEGIN PGP SIGNED MESSAGE----- ______________________________________________________________________________ SGI Security Advisory Title: IRIX O2 video security issue Number: 20020103-01-I Date: January 28, 2002 ______________________________________________________________________________ SGI provides this information freely to the SGI user community for its consideration, interpretation, implementation and use. SGI recommends that this information be acted upon as soon as possible. SGI 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 SGI 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 --- - ----------------------- SGI has been informed of a security problem specific to video i/o on SGI O2 systems. When the vcp Default Input is set to "Output Video", a remote user can log into the system, launch videoout and then videoin and can then see what is happening on the screen of the remote system (reading mail, etc...). This can be done regardless of xhosts or xauth settings on the remote system. SGI has investigated the issues and recommends the following steps for neutralizing the exposure. It is HIGHLY RECOMMENDED that these measures be implemented on ALL vulnerable SGI systems. - -------------- - --- Impact --- - -------------- This problem exists on all SGI O2 systems. This vulnerability may be exploited by a local user, a local account is required. The exploitation of this vulnerabilitiy can lead to a root compromise. - ------------------ - --- Workaround --- - ------------------ There is as yet no patch that addresses this issue. You can work around the problem by adding the following to /var/X11/xdm/Xstartup: # # Set the permissions of /dev/mvp so only the console user has access # if [ -r /dev/mvp ]; then chown $USER /dev/mvp chmod 600 /dev/mvp fi Add the following to /var/X11/xdm/Xreset: # # Reset the permissions on /dev/mvp # if [ -r /dev/mvp ]; then chown root /dev/mvp chmod 666 /dev/mvp fi These modifications change the ownership of the mvp device when a user logs in and back out. When the device is owned by the user with 600 permissions, nobody else is able to execute vcp, videoin, or videoout. Thus nobody can see what's on the console of the system. The /dev/mvp device only exists on O2s, so this problem does not impact other IRIX platforms (Octane, Onyx, etc.) After these modifications have been made, it is also not possible to login remotely and access other video signals. - ---------------- - --- Solution --- - ---------------- SGI has not released a patch for this issue. Please follow the workaround instructions above. - ------------------- - --- Information --- - ------------------- SGI Security Advisories can be found at: http://www.sgi.com/support/security/ and ftp://patches.sgi.com/support/free/security/advisories/ SGI Security Patches can be found at: http://www.sgi.com/support/security/ and ftp://patches.sgi.com/support/free/security/patches/ SGI patches for IRIX can be found at the following patch servers: http://support.sgi.com/irix/ and ftp://patches.sgi.com/ SGI freeware updates for IRIX can be found at: http://freeware.sgi.com/ SGI fixes for SGI open sourced code can be found on: http://oss.sgi.com/projects/ SGI patches and RPMs for Linux can be found at: http://support.sgi.com/linux/ or http://oss.sgi.com/projects/sgilinux-combined/download/security-fixes/ SGI patches for Windows NT or 2000 can be found at: http://support.sgi.com/nt/ IRIX 5.2-6.4 Recommended/Required Patch Sets can be found at: http://support.sgi.com/irix/ and ftp://patches.sgi.com/support/patchset/ IRIX 6.5 Maintenance Release Streams can be found at: http://support.sgi.com/colls/patches/tools/relstream/index.html IRIX 6.5 Software Update CDs can be obtained from: http://support.sgi.com/irix/swupdates/ The primary SGI anonymous FTP site for security advisories and patches is patches.sgi.com (216.32.174.211). Security advisories and patches are located under the URL ftp://patches.sgi.com/support/free/security/ For security and patch management reasons, ftp.sgi.com (mirrors patches.sgi.com security FTP repository) lags behind and does not do a real-time update. - ------------------------ - --- Acknowledgments ---- - ------------------------ SGI wishes to thank the SGI customer who discovered this vulnerability and the users of the Internet Community at large for their assistance in this matter. - ----------------------------------------- - --- SGI Security Information/Contacts --- - ----------------------------------------- If there are questions about this document, email can be sent to security-info@sgi.com. ------oOo------ SGI 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 advisories and patches is patches.sgi.com (216.32.174.211). Security advisories and patches are located under the URL ftp://patches.sgi.com/support/free/security/ The SGI 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 security-info@sgi.com. For assistance obtaining or working with security patches, please contact your SGI support provider. ------oOo------ SGI 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/security/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------ SGI provides a comprehensive customer World Wide Web site. This site is located at http://www.sgi.com/support/security/ . ------oOo------ If there are general security questions on SGI systems, email can be sent to security-info@sgi.com. 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, SGI is appropriately credited and the document retains and includes its valid PGP signature. -----BEGIN PGP SIGNATURE----- Version: 2.6.2 iQCVAwUBPFWb1rQ4cFApAP75AQGbYAP9H2CjBOH+2OGzMHshu0BDpJF7xE+7llca +KVb0Fl6XRfWoiq3WvWAMbJOZJwoM0YSxz4k7e5qI9HZ8ilSKlPqv75MHMCAb5zK 8G9otFTgMX4me6v8tVSHfblypjfBzaPwzQj5NSbsNVAq4HJSRnc5A6Ynzay4gs2V 0uMM+v+m4aY= =HixP -----END PGP SIGNATURE-----