[ SOURCE: http://www.secureroot.com/security/advisories/9641771132.html ] - ------------------------------------------------------------------------------ Sun Microsystems, Inc. Security Bulletin Bulletin Number: #00142 Date: June 4 1997 Cross-Ref: Title: Vulnerability in rpcbind - ------------------------------------------------------------------------------ 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. - ------------------------------------------------------------------------------ 1. Bulletins Topics Sun announces the release of patches for Solaris 2.5.1, 2.5, 2.4, and 2.3 (SunOS 5.5.1, 5.5, 5.4, and 5.3), that relate to a vulnerability in the rpcbind program, which can aid an attacker to gain unauthorized access if exploited. Sun strongly recommends that you install the patches listed in section 4 immediately on every affected system. 2. Who is Affected Vulnerable: SunOS versions 5.5.1, 5.5.1_x86, 5.5, 5.5_x86, 5.4, 5.4_x86, and 5.3. Not vulnerable: All other supported versions of SunOS This vulnerability is fixed in the upcoming release of Solaris. 3. Understanding the Vulnerability The rpcbind program is a server that converts RPC program numbers into universal addresses. When an RPC service is started, it tells rpcbind the address at which it is listening, and the RPC program numbers it is prepared to serve. When a client wishes to make an RPC call to a given program number, it first contacts rpcbind on the server machine to determine the address where RPC requests should be sent. Under Solaris 2.x, rpcbind listens not only on TCP port 111 and UDP port 111, but also on a UDP port number greater than 32770. The exact number depends on the OS release and architecture. This results in a large number of packet filters which intend to block access to rpcbind/portmapper being ineffective. Instead of sending requests to TCP or UDP port 111, the attacker simply sends them to the other UDP port. This vulnerability allows an attacker to obtain remote RPC program information even if TCP or UDP port 111 is being filtered. It can also aid an attacker to gain unauthorized access to hosts running vulnerable versions of the software. 4. List of Patches The vulnerability relating to rpcbind is fixed by the following patches: OS version Patch ID ---------- -------- SunOS 5.5.1 104331-02 SunOS 5.5.1_x86 104332-02 SunOS 5.5 104357-02 SunOS 5.5_x86 104358-02 SunOS 5.4 102070-03 SunOS 5.4_x86 102071-03 SunOS 5.3 102034-02 5. Checksum Table The checksum table below shows the BSD checksums (SunOS 5.x: /usr/ucb/sum), SVR4 checksums (SunOS 5.x: /usr/bin/sum), and the MD5 digital signatures for the above-mentioned patches that are available from: ftp://sunsolve1.sun.com/pub/patches/patches.html These checksums may not apply if you obtain patches from your answer centers. File Name BSD SVR4 MD5 - --------------- --------- --------- -------------------------------- 104331-02.tar.Z 64512 111 17253 222 29C2D5649C56A3D64E1F1DFCE3783842 104332-02.tar.Z 56808 111 23404 221 4B5D28F4A686166C4C147BE4E9563B8C 104357-02.tar.Z 27488 111 31772 222 316B03F737FC61DC09877C2BB822E7EE 104358-02.tar.Z 22598 110 46888 220 1665E8724D0A3DB401A00BE812630A37 102070-03.tar.Z 32763 100 14089 200 31FB11BC9D89A6D540F87624D4A2CFAE 102071-03.tar.Z 21217 100 18859 199 76DDAF2CAE25535A9AE932F3B0C98E3A 102034-02.tar.Z 23648 100 49973 199 243CD25673D87D0277F5CFE06E327347 - ------------------------------------------------------------------------------ Sun acknowledges with thanks Secure Networks, Inc. for their assistance in the preparation of this bulletin. - ------------------------------------------------------------------------------ APPENDICES A. Patches listed in this bulletin are available to all Sun customers via World Wide Web at: ftp://sunsolve1.sun.com/pub/patches/patches.html Customers with Sun support contracts can also obtain patches from local Sun answer centers and SunSITEs worldwide. B. To report or inquire about a security problem with Sun software, contact one or more of the following: - Your local Sun answer centers - Your representative computer security response team, such as CERT - Sun Security Coordination Team. Send email to: security-alert@sun.com C. To receive information or subscribe to our CWS (Customer Warning System) mailing list, send email to: security-alert@sun.com with a subject line (not body) containing one of the following commands: Command 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 the Security Coordination Team for response. REPORT [topic] The mail containing the text is treated as a security report and forwarded to the Security Coordination Team. We do not recommend that detailed problem descriptions be sent in plain text. SEND topic A short status summary or bulletin. For example, to retrieve a Security Bulletin #00138, supply the following in the subject line (not body): SEND #138 SUBSCRIBE Sender is added to our mailing list. To subscribe, supply the following in the subject line (not body): SUBSCRIBE cws your-email-address Note that your-email-address should be substituted by your email address. UNSUBSCRIBE Sender is removed from our mailing list. - ------------------------------------------------------------------------------