__________________________________________________________ The U.S. Department of Energy Computer Incident Advisory Capability ___ __ __ _ ___ / | /_\ / \___ __|__ / \ \___ __________________________________________________________ INFORMATION BULLETIN Sun libc/libnsl vulnerabilities (Sun Bulletin #00137a) December 13, 1996 18:00 GMT Number H-06a ______________________________________________________________________________ PROBLEM: A buffer over-run vulnerability exists in the libc and libnsl libraries under Solaris 2.5 and 2.5.1 that can allow an unauthorized user to gain access to the system and root privileges. PLATFORM: Solaris 2.5 and 2.5.1 ONLY; SunOS 4.1.X systems are not vulnerable. DAMAGE: An unauthorized user (whether internal or external) could gain access to the system and gain root privileges. SOLUTION: Apply the patches recommended by the vendor as listed below. ______________________________________________________________________________ VULNERABILITY Any Sun system running versions 2.5 or 2.5.1 of the Solaris ASSESSMENT: operating system could be attacked by a local or remote user and gain root access. A vulnerability script has been widely published to exploit this vulnerability. ______________________________________________________________________________ [ Begin Sun Bulletin ] ============================================================================= SUN MICROSYSTEMS SECURITY BULLETIN: #00137a, 11 Dec 1996 ============================================================================= ADDENDUM This is an amended version of Sun Microsystems Security Bulletin #00137, which discussed recently released security patches for Solaris 2.5 and 2.5.1. The changes correct two mistakes. No new information is provided. The original bulletin, released 20 Nov 1996, stated: Since the current version (v1.0) of SISS, the Solaris Internet Server Supplement, is based largely on 2.5.1 code, it too is vulnerable. In fact, SISS v1.0 (the only version to date) is *not* vulnerable to this attack. The original version of the bulletin also contained a typographical error. References to Solaris "5.1.1" should instead read "5.5.1". This amended version of the bulletin contains corrections for both errors. We regret any inconvenience caused by the inaccuracies in the original version of the bulletin. BULLETIN TOPICS In this bulletin Sun announces the release of security-related patches for Solaris 2.5 (SunOS 5.5) and Solaris 2.5.1 (SunOS 5.5.1). The patches relate to a single problem involving vulnerabilities in both the libc and libnsl libraries. Sun strongly recommends that you install these patches immediately on every affected system. An exploitation script was publicly released earlier this week for this vulnerability and the script is now widely distributed. Many 2.5 and 2.5.1 systems are therefore currently vulnerable to attack. Earlier versions of SunOS, including 4.1.x, do not have the bug and are not vulnerable. As of this writing Sun is aware of no successful attacks based on this problem. I. Who is Affected, and What to Do II. Understanding the Vulnerability III. List of Patches IV. Checksum Table APPENDICES A. How to obtain Sun security patches B. How to report or inquire about Sun security problems C. How to obtain Sun security bulletins or short status updates Send Replies or Inquiries To: Mark Graff Sun Security Coordinator MS MPK17-103 2550 Garcia Avenue Mountain View, CA 94043-1100 Phone: 415-786-5274 Fax: 415-786-7994 E-mail: security-alert@Sun.COM Sun acknowledges with thanks the CERT Coordination Center (Carnegie Mellon University), AUSCERT, and Marko Laakso (University of Oulu) for their assistance in the preparation of this bulletin. Sun, CERT/CC, and AUSCERT are all members of FIRST, the Forum of Incident Response and Security Teams. For more information about FIRST, visit the FIRST web site at "http://www.first.org/". Keywords: gethostbyname, root, libc, libnsl Patchlist: 103187-09, 103188-09, 103612-06, 103613-06, 103614-06 Cross-Ref: ----------- Permission is granted for the redistribution of this Bulletin, so long as the Bulletin is not edited and is attributed to Sun Microsystems. Portions may also be excerpted for re-use in other security advisories so long as proper attribution is included. Any other use of this information without the express written consent of Sun Microsystems is prohibited. Sun Microsystems expressly disclaims all liability for any misuse of this information by any third party. ============================================================================= SUN MICROSYSTEMS SECURITY BULLETIN: #00137a, 11 Dec 1996 ============================================================================= I. Who is Affected, and What to Do Sun has verified that this vulnerability affects all supported Solaris 2.5 (SunOS 5.5) and Solaris 2.5.1 (SunOS 5.5.1) systems. Earlier versions of SunOS, including 4.1.x, do not have the bug and are not vulnerable. Installing and running the software provided in these patches completely closes the vulnerability. For information about how to obtain these and other Sun patches, see Appendix A. To see which version of SunOS your system is running, use a command such as: % uname -a If your system is running SunOS 5.5 or 5.5.1, it is vulnerable. II. Understanding the Vulnerability If exploited, this vulnerability can be used to gain root access on attacked systems. The attack could be initiated from a remote system. Even penetration through a firewall may be possible, depending upon which services and applications (such as rlogin) are allowed to pass through the firewall. Because this vulnerability is located in two key system libraries, many setuid/setgid system utilities are affected and possibly exploitable. There has been a buffer over-run vulnerability discovered in both the libc and the libnsl libraries under Solaris 2.5/2.5.1. Many setuid and setgid programs, as well as network programs running with root privileges, are dynamically linked against these libraries. This vulnerability has the potential for any program using these libraries, running with root privileges, to be exploited, giving root privileges. III. List of Patches The patches required to close this vulnerability are listed below. A. Solaris 2.x (SunOS 5.x) patches Patches which replace the affected libraries and executables are available for every supported version of SunOS 5.x. OS version Patch ID ---------- --------- SunOS 5.5 103187-09 SunOS 5.5_X86 103188-09 SunOS 5.5.1 103612-06 SunOS 5.5.1_x86 103613-06 SunOS 5.5.1_ppc 103614-06 B. Solaris 1.x (SunOS 4.1.x) patches No patches are needed for SunOS 4.1.x, which is not vulnerable. IV. Checksum Table In the checksum table we show the BSD and SVR4 checksums and MD5 digital signatures for the compressed tar archives. File BSD SVR4 MD5 Name Checksum Checksum Digital Signature --------------- ----------- --------- -------------------------------- 103187-09.tar.Z 55543 2779 1318 5557 2AF86E9126BB8B0505743D0283C175A6 103188-09.tar.Z 21952 2523 13621 5046 E0455AAC6DF587E9F9EC88082B9613B2 103612-06.tar.Z 29415 2752 38423 5503 56DF3214D8C5CC58C9AC223C9C7ACEBC 103613-06.tar.Z 30698 2501 29921 5002 7E27DF259B595231188D2725E2B6AE59 103614-06.tar.Z 05172 2766 46856 5532 193E63B9C5E2B829D59B1FCBE2E2981F The checksums shown above are from the BSD-based checksum (on 4.1.x, /bin/sum; on SunOS 5.x, /usr/ucb/sum) and from the SVR4 version on on SunOS 5.x (/usr/bin/sum). APPENDICES A. How to obtain Sun security patches 1. If you have a support contract Customers with Sun support contracts can obtain any patches listed in this bulletin (and any other patches--and a list of patches) from: - SunSolve Online - Local Sun answer centers, worldwide - SunSITEs worldwide The patches are available via World Wide Web at http://sunsolve.sun.com. You should also contact your answer center if you have a support contract and: - You need assistance in installing a patch - You need additional patches - You want an existing patch ported to another platform - You believe you have encountered a bug in a Sun patch - You want to know if a patch exists, or when one will be ready 2. If you do not have a support contract Customers without support contracts may now obtain security patches, "recommended" patches, and patch lists via SunSolve Online. Sun does not furnish patches to any external distribution sites other than the ones mentioned here. The ftp.uu.net and ftp.eu.net sites are no longer supported. 3. About the checksums So that you can quickly verify the integrity of the patch files themselves, we supply in each bulletin checksums for the tar archives. Occasionally, you may find that the listed checksums do not match the patches on the SunSolve or SunSite database. This does not necessarily mean that the patch has been tampered with. More likely, a non-substantive change (such as a revision to the README file) has altered the checksum of the tar file. The SunSolve patch database is refreshed nightly, and will sometimes contain versions of a patch newer than the one on which the checksums were based. In the future we may provide checksum information for the individual components of a patch as well as the compressed archive file. This would allow customers to determine, if need be, which file(s) have been changed since we issued the bulletin containing the checksums. In the meantime, if you would like assistance in verifying the integrity of a patch file please contact this office or your local answer center. B. How to report or inquire about Sun security problems If you discover a security problem with Sun software or wish to inquire about a possible problem, contact one or more of the following: - Your local Sun answer centers - Your representative computer security response team, such as CERT - This office. Address postal mail to: Sun Security Coordinator MS MPK17-103 2550 Garcia Avenue Mountain View, CA 94043-1100 Phone: 415-786-5274 Fax: 415-786-7994 E-mail: security-alert@Sun.COM We strongly recommend that you report problems to your local Answer Center. In some cases they will accept a report of a security bug even if you do not have a support contract. An additional notification to the security-alert alias is suggested but should not be used as your primary vehicle for reporting a bug. C. How to obtain Sun security bulletins or short status updates 1. Subscription information Sun Security Bulletins are available free of charge as part of our Customer Warning System. It is not necessary to have a Sun support contract in order to receive them. To receive information or to subscribe or unsubscribe from our mailing list, send mail to security-alert@sun.com with a subject line containing one of the following commands. Subject Information Returned/Action Taken ------- --------------------------------- HELP An explanation of how to get information LIST A list of current security topics QUERY [topic] The mail containing the question is relayed to a Security Coordinator for a response. REPORT [topic] The mail containing the text is treated as a security bug report and forwarded to a Security Coordinator for handling. Please note that this channel of communications does not supersede the use of Sun Solution Centers for this purpose. 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Obtaining old bulletins Sun Security Bulletins are available via the security-alert alias and on SunSolve. Please try these sources first before contacting this office for old bulletins. ------------ [ End Sun Bulletin ] _______________________________________________________________________________ CIAC wishes to acknowledge the contributions of Sun Microsystems 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. 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LAST 10 CIAC BULLETINS ISSUED (Previous bulletins available from CIAC) H-07: Sendmail SIGHUP-smtpd Vulnerability H-08: lpr Buffer Overrun Vulnerability H-09: HP 9000 Access Vulnerability H-10: HP-UX Security Vulnerabilities (passwd, fpkg2swpkg, newgrp) H-11: sendmail Group Permissions Vulnerability H-12: IBM AIX(r) 'SYN Flood' and 'Ping o' Death' Vulnerabilities H-13: IBM AIX(r) Security Vulnerabilities (gethostbyname, lquerypv) H-14: SGI IRIX Vulnerabilities (systour, OutOfBox, cdplayer, datman) H-15: Korn Shell (ksh) suid_exec Vulnerability H-16: HP-UX Security Vulnerabilities (chfn, Remote Watch) RECENT CIAC NOTES ISSUED (Previous Notes available from CIAC) Notes 07 - 3/29/95 A comprehensive review of SATAN Notes 08 - 4/4/95 A Courtney update Notes 09 - 4/24/95 More on the "Good Times" virus urban legend Notes 10 - 6/16/95 PKZ300B Trojan, Logdaemon/FreeBSD, vulnerability in S/Key, EBOLA Virus Hoax, and Caibua Virus Notes 11 - 7/31/95 Virus Update, Hats Off to Administrators, America On-Line Virus Scare, SPI 3.2.2 Released, The Die_Hard Virus Notes 12 - 9/12/95 Securely configuring Public Telnet Services, X Windows, beta release of Merlin, Microsoft Word Macro Viruses, Allegations of Inappropriate Data Collection in Win95 Notes 96-01 - 3/18/96 Java and JavaScript Vulnerabilities, FIRST Conference Announcement, Security and Web Search Engines, Microsoft Word Macro Virus Update