Sun RPC xdr_array buffer overflow

-- Brian Tao (BT300, taob@risc.org) "Though this be madness, yet there is method in't" ---------- Forwarded message ---------- From: Dave Ahmad da@securityfocus.com To: bugtraq@securityfocus.com Date: Wed, 31 Jul 2002 11:05:00 -0600 (MDT) Subject: [Bugtraq] Remote Buffer Overflow Vulnerability in Sun RPC -----BEGIN PGP SIGNED MESSAGE----- Internet Security Systems Security Brief July 31, 2002 Remote Buffer Overflow Vulnerability in Sun RPC Synopsis: Internet Security Systems (ISS) X-Force has discovered a buffer overflow in the xdr_array filter primitive. This function is a part of the Sun RPC library, and it is used in multiple RPC services. Any native or third party software that uses the xdr_array function may be vulnerable. Vulnerable RPC services are installed and enabled by default on the affected software versions. Impact: The buffer overflow vulnerability can allow remote attackers to execute arbitrary commands on a target system with superuser privileges. Attackers pose the most serious risk when attacking unprotected networks, or improperly protected networks Affected Versions: Sun Microsystems Solaris 2.5.1 Sun Microsystems Solaris 2.6 Sun Microsystems Solaris 7 Sun Microsystems Solaris 8 Sun Microsystems Solaris 9 Note: The versions above were tested and found to be vulnerable. Additional commercial and open-source Unix operating systems use implementations of Sun RPC, and may also be vulnerable. For the complete ISS X-Force Security Advisory, please visit: http://bvlive01.iss.net/issEn/delivery/xforce/alertdetail.jsp?oid=20823 ______ About Internet Security Systems (ISS) Founded in 1994, Internet Security Systems (ISS) (Nasdaq: ISSX) is a pioneer and world leader in software and services that protect critical online resources from an ever-changing spectrum of threats and misuse. Internet Security Systems is headquartered in Atlanta, GA, with additional operations throughout the Americas, Asia, Australia, Europe and the Middle East. Copyright (c) 2002 Internet Security Systems, Inc. All rights reserved worldwide. Permission is hereby granted for the electronic redistribution of this document. It is not to be edited or altered in any way without the express written consent of the Internet Security Systems X-Force. If you wish to reprint the whole or any part of this document in any other medium excluding electronic media, please email xforce@iss.net for permission. Disclaimer: The information within this paper may change without notice. Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user's risk. In no event shall the author/distributor (Internet Security Systems X-Force) be held liable for any damages whatsoever arising out of or in connection with the use or spread of this information. X-Force PGP Key available on MIT's PGP key server and PGP.com's key server, as well as at http://www.iss.net/security_center/sensitive.php Please send suggestions, updates, and comments to: X-Force xforce@iss.net of Internet Security Systems, Inc. -----BEGIN PGP SIGNATURE----- Version: 2.6.2 iQCVAwUBPUgOXzRfJiV99eG9AQG3NwQAqgUoyqctQpqzo6aZGXGVPFaSZtv5Qu85 kfPVlyJXL6crPQbelYtwAWolBI7qYGSE74lo4jRcpeI5lG/K8p39X66zHaZPAqZ7 fYZyEfIvJ3gCqtbowZSNUAvm1jdoFa0RVTwbuKmNPSGcDTebi+o7buWEG37HzdKO YUEiRp8erpg= =VTC/ -----END PGP SIGNATURE----- --__--__-- _______________________________________________ Bugtraq mailing list Bugtraq@lists.corp.attcanada.ca http://lists.corp.attcanada.ca/mailman/listinfo/bugtraq End of Bugtraq Digest_______________________________________________ Bugtraq mailing list Bugtraq@lists.corp.attcanada.ca http://lists.corp.attcanada.ca/mailman/listinfo/bugtraq ---------- Forwarded message ---------- Date: Wed, 31 Jul 2002 19:46:06 -0700 (PDT) From: FreeBSD Security Advisories security-advisories@freebsd.org To: FreeBSD Security Advisories security-advisories@freebsd.org Subject: FreeBSD Security Advisory FreeBSD-SA-02:34.rpc -----BEGIN PGP SIGNED MESSAGE----- ============================================================================= FreeBSD-SA-02:34.rpc Security Advisory The FreeBSD Project Topic: Sun RPC XDR decoder contains buffer overflow Category: core Module: libc Announced: 2002-07-31 Credits: ISS X-Force Affects: All releases of FreeBSD up to and including 4.6.1-RELEASE-p3 Corrected: 2002-07-31 14:45:29 UTC (RELENG_4) 2002-07-31 14:47:02 UTC (RELENG_4_6) 2002-07-31 14:49:18 UTC (RELENG_4_5) 2002-07-31 14:50:18 UTC (RELENG_4_4) FreeBSD only: NO I. Background Sun RPC is a remote procedure call framework which allows clients to invoke procedures in a server process over a network somewhat transparently. XDR is a mechanism for encoding data structures for use with RPC. NFS, NIS, and many other network services are built upon Sun RPC. The FreeBSD C runtime library (libc) contains an XDR encoder/decoder derived from Sun's RPC implementation. II. Problem Description An error in the calculation of memory needed for unpacking arrays in the XDR decoder can result in a heap buffer overflow. III. Impact Any application using Sun RPC may be vulnerable to the heap buffer overflow. Depending upon the application, this vulnerability may be exploitable and lead to arbitrary code execution. Though no exploits are known to exist currently, many RPC-based services run as the superuser (such as NFS, the NIS server, rpc.statd, and others) and thus this vulnerability should be considered high-risk. No RPC-based services are enabled by default in FreeBSD installations. IV. Workaround Do not run any RPC-based services. The RPC-based services running on a machine may be determined by: # rpcinfo -p <hostname> To disable any RPC-based services at next boot, add (or change if it is already present) the following lines in /etc/rc.conf: portmap_enable="NO" nfs_client_enable="NO" nfs_server_enable="NO" nis_client_enable="NO" nis_server_enable="NO" V. Solution Do one of the following: 1) Upgrade your vulnerable system to 4.6-STABLE; or to the RELENG_4_6, RELENG_4_5, or RELENG_4_4 security branch dated after the correction date (4.6.1-RELEASE-p4, 4.5-RELEASE-p12, or 4.4-RELEASE-p19). 2) To patch your present system: The following patch has been verified to apply to FreeBSD 4.4, 4.5, and 4.6 systems. a) Download the relevant patch from the location below, and verify the detached PGP signature using your PGP utility. # fetch ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/patches/SA-02:34/rpc.patch # fetch ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/patches/SA-02:34/rpc.patch.asc b) Execute the following commands as root: # cd /usr/src # patch < /path/to/patch c) Recompile the operating system as described in URL:http://www.freebsd.org/doc/handbook/makeworld.html. Note that any statically linked applications that are not part of the base system (i.e. from the Ports Collection or other 3rd-party sources) must be recompiled if they use Sun RPC. All affected applications must be restarted in order to use the corrected library. Though it is not required, rebooting may be the easiest way to accomplish this. VI. Correction details The following list contains the revision numbers of each file that was corrected in FreeBSD. Path Revision Branch - ------------------------------------------------------------------------- src/lib/libc/xdr/xdr_array.c RELENG_4 1.8.2.2 RELENG_4_6 1.8.10.2 RELENG_4_5 1.8.8.2 RELENG_4_4 1.8.6.2 src/sys/conf/newvers.sh RELENG_4_6 1.44.2.23.2.9 RELENG_4_5 1.44.2.20.2.13 RELENG_4_4 1.44.2.17.2.18 - ------------------------------------------------------------------------- VII. References URL:http://online.securityfocus.com/archive/1/285308 URL:http://bvlive01.iss.net/issEn/delivery/xforce/alertdetail.jsp?oid=20823 -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.0.7 (FreeBSD) iQCVAwUBPUigCVUuHi5z0oilAQHdiAP8CcsDW7DufF7wYg0FcgoyQ2ugiBe21lgo YfAGfRcfxPtoZcmMApK3I5jUd/MRWCxBT3+ZcwtKe/aNH4hFlcpfcH5WYLVlrCgH 5QuVRR8dUfF/cWr8ejPq6xjXysUd/jMZWRQjAV8pCr+ngGSeMUeXQshB71ZyA5nk YrBUd7Uoenk= =lwhC -----END PGP SIGNATURE----- This is the moderated mailing list freebsd-announce. The list contains announcements of new FreeBSD capabilities, important events and project milestones. See also the FreeBSD Web pages at http://www.freebsd.org To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-announce" in the body of the message