__________________________________________________________ The U.S. Department of Energy Computer Incident Advisory Capability ___ __ __ _ ___ / | /_\ / \___ __|__ / \ \___ __________________________________________________________ INFORMATION BULLETIN Sendmail Restricted Shell (smrsh) and Check_Relay Vulnerabilities December 19, 2002 21:00 GMT Number N-030 [REVISED 20 December 2002] [REVISED 10 January 2003] [REVISED 1 October 2003] ______________________________________________________________________________ PROBLEM: 1) Sendmail Restricted Shell (smrsh) may let local users bypass restrictions to execute code, or possibly gain root access. 2) A remote user with the ability to control a DNS server or spoof the DNS may be able to bypass a target server's sendmail access controls and send mail to or via that server. PLATFORM: Multiple vendor products might be affected when used in conjunction with Sendmail, such as Linux and UNIX. HP-UX B.11.00, B.11.11, B.11.22 running sendmail version 8.11.1 only DAMAGE: 1) The potential vulnerability may allow authorized users to execute unauthorized programs. 2) A remote user with ability to spoof the DNS can bypass sendmail access controls and send mail to or through the server. SOLUTION: Check with your vendor for platform-specific solutions. Sendmail.org has released 8.12.7, which corrects these vulnerabilities. ______________________________________________________________________________ VULNERABILITY The risk is MEDIUM. 1) The vulnerability is only exploitable ASSESSMENT: by local users and only allows execution of unauthorized programs. 2) Only a remote user who already has the ability to control a DNS server or spoof a DNS could exploit this vulnerability. ______________________________________________________________________________ LINKS: CIAC BULLETIN: http://www.ciac.org/ciac/bulletins/n-030.shtml VENDOR BULLETINS: Sendmail.org: http://www.sendmail.org/8.12.7.html Hewlett-Packard: ftp://smrsh:smrsh1@hprc.external.hp.com/ or ftp://smrsh:smrsh1@192.170.19.51/ http://www.software.hp.com/cgi-bin/swdepot_parser.cgi/ cgi/displayProductInfo.pl?productNumber=SMAIL811 SGI: ftp://patches.sgi.com/support/free/security/ advisories/20030101-01-P ______________________________________________________________________________ REVISION HISTORY: 10/1/03 - Added Hewlett Packard's link and updated the Hewlett Packard's Security Bulletin HPSBUX0212-234 SSRT2432 smrsh restrictions bypass (rev 2.) [****** START HEWLET PACKARD SECURITY BULLETIN ******] **REVISED 02** Source: HEWLETT-PACKARD COMPANY SECURITY BULLETIN: HPSBUX0212-234 Originally issued: 19 December 2002 Last revision: 30 September 2003 SSRT2432 smrsh restrictions bypass (rev.2) ----------------------------------------------------------------- NOTICE: There are no restrictions for distribution of this Bulletin provided that it remains complete and intact. The information in the following Security Bulletin should be acted upon as soon as possible. Hewlett-Packard Company will not be liable for any consequences to any customer resulting from customer's failure to fully implement instructions in this Security Bulletin as soon as possible. ----------------------------------------------------------------- PROBLEM: Sendmail Restricted Shell (smrsh) may let local users bypass restrictions to execute code. IMPACT: The potential vulnerability may allow authorized users to execute unauthorized programs. PLATFORM: HP-UX B.11.00, B.11.11, B.11.22 running sendmail version 8.11.1 ONLY. SOLUTION: B.11.22 - PHNE_28409 or subsequent B.11.11 - Web upgrade B.11.00 - Web upgrade MANUAL ACTIONS: Yes - Update Update B.11.00 and B.11.11. A patch is available for B.11.22. No manual action is required for B.11.22. AVAILABILITY: The patch and web upgrades are available now. CHANGE SUMMARY: Rev.01 - Only sendmail version 8.11.1 is vulnerable. Rev.02 - Patch and web upgrades are available. Added AFFECTED VERSIONS section. ----------------------------------------------------------------- A. Background Sendmail Restricted Shell (smrsh) may let local users bypass restrictions to execute code. The only vulnerable version delivered on HP-UX is sendmail 8.11.1. This version is available as a web upgrade for HP-UX B.11.00 and B.11.11. Sendmail version 8.11.1 is delivered with HP-UX B.11.22. **REVISED 02** --> AFFECTED VERSIONS The following is a list by HP-UX revision of affected filesets and the fileset revision or patch containing the fix. To determine if a system has an affected version, search the output of "swlist -a revision -l fileset" for an affected fileset, then determine if a fixed revision or the applicable patch is installed. HP-UX B.11.22 ============= InternetSrvcs.INETSVCS2-RUN InternetSrvcs.INETSVCS-RUN fix: PHNE_28409 or subsequent HP-UX B.11.11 ============= SMAIL-811.INETSVCS-SMAIL fix: revision B.11.11.01.005 or subsequent (web upgrade to Sendmail 8.11.1 Version 5 or subsequent) HP-UX B.11.00 ============= SMAIL-811.INETSVCS-SMAIL fix: revision B.11.00.01.004 or subsequent (web upgrade to Sendmail 8.11.1 Version 4 or subsequent) --> END AFFECTED VERSIONS HP Tru64 UNIX is not vulnerable to this reported problem. B. Recommended solution **REVISED 02** -->HP-UX B.11.22 sendmail 8.11.1 PHNE_28409 is now available. -->HP-UX B.11.00 and B.11.11 sendmail 8.11.1 A web upgrade is available from software.hp.com: C. To subscribe to automatically receive future NEW HP Security Bulletins from the HP IT Resource Center via electronic mail, do the following: Use your browser to get to the HP IT Resource Center page at: http://itrc.hp.com Use the 'Login' tab at the left side of the screen to login using your ID and password. Use your existing login or the "Register" button at the left to create a login, in order to gain access to many areas of the ITRC. Remember to save the User ID assigned to you, and your password. In the left most frame select "Maintenance and Support". Under the "Notifications" section (near the bottom of the page), select "Support Information Digests". To -subscribe- to future HP Security Bulletins or other Technical Digests, click the check box (in the left column) for the appropriate digest and then click the "Update Subscriptions" button at the bottom of the page. or To -review- bulletins already released, select the link (in the middle column) for the appropriate digest. NOTE: Using your itrc account security bulletins can be found here: http://itrc.hp.com/cki/bin/doc.pl/screen=ckiSecurityBulletin To -gain access- to the Security Patch Matrix, select the link for "The Security Bulletins Archive". (near the bottom of the page) Once in the archive the third link is to the current Security Patch Matrix. Updated daily, this matrix categorizes security patches by platform/OS release, and by bulletin topic. Security Patch Check completely automates the process of reviewing the patch matrix for 11.XX systems. Please note that installing the patches listed in the Security Patch Matrix will completely implement a security bulletin _only_ if the MANUAL ACTIONS field specifies "No." The Security Patch Check tool can verify that a security bulletin has been implemented on HP-UX 11.XX systems providing that the fix is completely implemented in a patch with no manual actions required. The Security Patch Check tool cannot verify fixes implemented via a product upgrade. For information on the Security Patch Check tool, see: http://www.software.hp.com/cgi-bin/swdepot_parser.cgi/cgi/ displayProductInfo.pl?productNumber=B6834AA The security patch matrix is also available via anonymous ftp: ftp://ftp.itrc.hp.com/export/patches/hp-ux_patch_matrix/ On the "Support Information Digest Main" page: click on the "HP Security Bulletin Archive". The PGP key used to sign this bulletin is available from several PGP Public Key servers. The key identification information is: 2D2A7D59 HP Security Response Team (Security Bulletin signing only) Fingerprint = 6002 6019 BFC1 BC62 F079 862E E01F 3AFC 2D2A 7D59 If you have problems locating the key please write to security-alert@hp.com. Please note that this key is for signing bulletins only and is not the key returned by sending 'get key' to security-alert@hp.com. D. To report new security vulnerabilities, send email to security-alert@hp.com Please encrypt any exploit information using the security-alert PGP key, available from your local key server, or by sending a message with a -subject- (not body) of 'get key' (no quotes) to security-alert@hp.com. ----------------------------------------------------------------- (c)Copyright 2003 Hewlett-Packard Company Hewlett-Packard Company shall not be liable for technical or editorial errors or omissions contained herein. The information in this document is subject to change without notice. Hewlett-Packard Company and the names of HP products referenced herein are trademarks and/or service marks of Hewlett-Packard Company. Other product and company names mentioned herein may be trademarks and/or service marks of their respective owners. ________________________________________________________________ [****** END HEWLET PACKARD SECURITY BULLETIN ******] ______________________________________________________________________________ CIAC wishes to acknowledge the contributions of Sendmail.org, Hewlett-Packard Company, Silicon Graphics, Inc., and SecurityTracker.com 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. 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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