__________________________________________________________ The U.S. Department of Energy Computer Incident Advisory Center ___ __ __ _ ___ / | /_\ / \___ __|__ / \ \___ __________________________________________________________ INFORMATION BULLETIN Sun ypbind Buffer Overflow Vulnerability [AusCERT Advisory AA-2001.03] June 29, 2001 22:00 GMT Number L-103 ______________________________________________________________________________ PROBLEM: A buffer overflow vulnerability exists in ypbind. PLATFORM: SunOS 5.8, 5.8_x86, 5.7, 5.7_x86, 5.6, 5.6_x86, 5.5.1, 5.5.1_x86, 5.5, 5.5_x86, 5.4, and 5.4_x86 DAMAGE: This vulnerability may allow a local or remote user to gain root access and, therefore, complete control of the system. SOLUTION: Apply the patches described below. ______________________________________________________________________________ VULNERABILITY The risk is HIGH. The vulnerability results in a root ASSESSMENT: compromise, it is remotely exploitable, and is widely publicized. ______________________________________________________________________________ [****** Start AusCERT Advisory ******] =========================================================================== AA-2001.03 AUSCERT Advisory Sun Microsystems ypbind Buffer Overflow Vulnerability 22 June 2001 Last Revised: -- - --------------------------------------------------------------------------- AusCERT has received information that a vulnerability exists in the program ypbind for Solaris 8, 7, 2.6, 2.5.1, 2.5, and 2.4 (SunOS 5.8, 5.7, 5.6, 5.5.1, 5.5, and 5.4). This vulnerability may allow local and/or remote users to gain root privileges. AusCERT recommends that sites take the steps outlined in section 3 as soon as possible. This advisory will be updated as more information becomes available. - --------------------------------------------------------------------------- 1. Description ypbind is the daemon that maintains binding information for clients and servers that are configured to use NIS. A buffer overflow vulnerability exists in ypbind which may be exploited by a malicious local or remote user to obtain root access. Sun Microsystems has provided the following details of vulnerable and non-vulnerable versions of SunOS. Vulnerable versions of SunOS are: 5.8, 5.8_x86, 5.7, 5.7_x86, 5.6, 5.6_x86, 5.5.1, 5.5.1_x86, 5.5, 5.5_x86, 5.4, and 5.4_x86. SunOS 5.8 01/01 and SunOS 5.8_x86 01/01 and all later SunOS 5.8 update releases are NOT vulnerable. SunOS 5.8 and SunOS 5.8_x86 with Maintenance Update (MU) 3 or a later MU applied are also NOT vulnerable. Sites can determine if they are running one of the afore-mentioned non-vulnerable versions of SunOS by checking the contents of the /etc/release file. Vendor patches are available - refer to Section 3 for details. 2. Impact This vulnerability may allow local or remote users to gain root privileges. 3. Solution AusCERT recommends that official vendor patches be installed. Sun patches that address this vulnerability are listed below and are available at: http://sunsolve.sun.com/securitypatch OS Version Patch ID __________ _________ SunOS 5.8 110322-01 SunOS 5.8_x86 110323-01 SunOS 5.7 108750-02 SunOS 5.7_x86 108751-02 SunOS 5.6 105403-04 SunOS 5.6_x86 105404-04 SunOS 5.5.1 105165-04 SunOS 5.5.1_x86 105166-04 SunOS 5.5 105169-04 SunOS 5.5_x86 105170-04 SunOS 5.4 101973-41 SunOS 5.4_x86 101974-41 Checksums for these patches are available at: ftp://sunsolve.sun.com/pub/patches/CHECKSUMS 4.0 Vendor Information Sun have released security bulletin #00203 regarding this vulnerability which is publicly available at the following URL: http://sunsolve.sun.com/security - --------------------------------------------------------------------------- AusCERT would like to acknowledge the assistance of the Sun Security Coordination Team as well as Mark Dowd and Stephen James of IT Audit & Consulting in producing this Advisory. - --------------------------------------------------------------------------- AusCERT has made every effort to ensure that the information contained in this document is accurate. However, the decision to use the information described is the responsibility of each user or organisation. The appropriateness of this document for an organisation or individual system should be considered before application in conjunction with local policies and procedures. AusCERT takes no responsibility for the consequences of applying the contents of this document. If you believe that your system has been compromised, contact AusCERT or your representative in FIRST (Forum of Incident Response and Security Teams). AusCERT maintains an anonymous FTP service which is found on: ftp://ftp.auscert.org.au/pub/. This archive contains past SERT and AusCERT Advisories, and other computer security information. AusCERT also maintains a World Wide Web service which is found on: http://www.auscert.org.au/. Internet Email: auscert@auscert.org.au Facsimile: (07) 3365 7031 Telephone: (07) 3365 4417 (International: +61 7 3365 4417) AusCERT personnel answer during Queensland business hours which are GMT+10:00 (AEST). On call after hours for emergencies. Postal: Australian Computer Emergency Response Team The University of Queensland Brisbane Qld 4072 AUSTRALIA ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Revision History ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ [****** End AusCERT Advisory ******] _______________________________________________________________________________ CIAC wishes to acknowledge the contributions of AusCERT for the information contained in this bulletin. _______________________________________________________________________________ CIAC, the Computer Incident Advisory Center, 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: +1 925-422-8193 (7x24) FAX: +1 925-423-8002 STU-III: +1 925-423-2604 E-mail: ciac@ciac.org Previous CIAC notices, anti-virus software, and other information are available from the CIAC Computer Security Archive. World Wide Web: http://www.ciac.org/ Anonymous FTP: ftp.ciac.org 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. Reference herein to any specific commercial products, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation or favoring by the United States Government or the University of California. 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