-----BEGIN PGP SIGNED MESSAGE----- _____________________________________________________________________________ SGI Security Advisory Title: IRIX default root umask and coredumps Number: 20020902-01-I Date: September 18, 2002 _____________________________________________________________________________ - ----------------------- - --- Issue Specifics --- - ----------------------- IRIX 6.5's umask setting is applied to system coredumps. While that is not a bug, it is a design decision that has consequences for the security of an IRIX system. Since the default umask for the root user is 022, root's coredumps are created with permissions of "-rw-r--r--". That means unprivileged users can read them. Coredumps can potentially contain sensitive information, and this could be used to compromise system security. SGI 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 --- - -------------- The "022" root umask is configured by default on IRIX 6.5 systems. To determine the version of IRIX you are running, execute the following command: # /bin/uname -R That will return a result similar to the following: # 6.5 6.5.16f The first number ("6.5") is the release name, the second ("6.5.16f" in this case) is the extended release name. The extended release name is the "version" we refer to throughout this document. To see what root's umask is currently set to, execute the following commands: $ su - # umask If the system returns "022" and the IRIX version is earlier than 6.5.15, then the system may be vulnerable. - ---------------------------- - --- Temporary Workaround --- - ---------------------------- SGI understands that there are times when upgrading the operating system or installing patches are inconvenient or not possible. In those instances, we recommend the following workaround: Change the root user's umask to something that will not allow unprivileged users to read files created by root: $ su - # umask 077 or add "umask 077" to /etc/profile or the global configuration files corresponding to what shell root uses. There can be negative side effects to this, however, as it may be necessary for users to be able to read some files created by root, and in those cases root would have to manually chmod the files to the appropriate permissions. SGI recommends upgrading to IRIX 6.5.15 or later, where SGI has introduced a new systune variable called "coremask". Using systune to tune the value of coremask to an appropriate value for corefiles will allow root to have a value separate from root's umask to control the permissions of core files. Setting the coremask variable is documented in /var/sysgen/mtune/kernel on IRIX 6.5.15 and later systems. - ---------------- - --- Solution --- - ---------------- Please update to IRIX 6.5.15 if you would like to implement this new functionality. OS Version Vulnerable? Patch # Other Actions ---------- ----------- ------- ------------- IRIX 3.x unknown Note 1 IRIX 4.x unknown Note 1 IRIX 5.x unknown Note 1 IRIX 6.0.x unknown Note 1 IRIX 6.1 unknown Note 1 IRIX 6.2 unknown Note 1 IRIX 6.3 unknown Note 1 IRIX 6.4 unknown Note 1 IRIX 6.5 yes Notes 2 & 3 IRIX 6.5.1 yes Notes 2 & 3 IRIX 6.5.2 yes Notes 2 & 3 IRIX 6.5.3 yes Notes 2 & 3 IRIX 6.5.4 yes Notes 2 & 3 IRIX 6.5.5 yes Notes 2 & 3 IRIX 6.5.6 yes Notes 2 & 3 IRIX 6.5.7 yes Notes 2 & 3 IRIX 6.5.8 yes Notes 2 & 3 IRIX 6.5.9 yes Notes 2 & 3 IRIX 6.5.10 yes Notes 2 & 3 IRIX 6.5.11 yes IRIX 6.5.12 yes IRIX 6.5.13 yes IRIX 6.5.14 yes IRIX 6.5.15 no IRIX 6.5.16 no IRIX 6.5.17 no NOTES 1) This version of the IRIX operating has been retired. Upgrade to an actively supported IRIX operating system. See http://support.sgi.com/irix/news/index.html#policy for more information. 2) If you have not received an IRIX 6.5.X CD for IRIX 6.5, contact your SGI Support Provider or URL: http://support.sgi.com/irix/swupdates/ 3) Upgrade to IRIX 6.5.15 or later. See the following website: http://support.sgi.com/colls/patches/tools/relstream/index.html - ------------------------ - --- Acknowledgments ---- - ------------------------ SGI wishes to thank FIRST and the users of the Internet Community at large for their assistance in this matter. - ------------- - --- Links --- - ------------- 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. - ----------------------------------------- - --- 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 <YourEmailAddress such as aaanalyst@sgi.com > end ^d In the example above, <YourEmailAddress> 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 iQCVAwUBPYineLQ4cFApAP75AQGS1AP+NWZzMxlNhwYPrldvejLlu6+1Uwp+dlCu UEjT62TdF928797vpleWWhRA6VmrWZMzBAK7GoXQ7UzjFLo6Pf29FI0GEDoaMZSF qV/lPltM8tXxlqJiIRlAt8L2Fw/oILO77S6pqt9DsStgQ+d8iHL0L7OuhZZXQKtC E6IgHAQ7Pms= =CAc5 -----END PGP SIGNATURE-----