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- -----BEGIN PGP SIGNED MESSAGE-----
-
- =============================================================================
- CERT(sm) Advisory CA-95:08
- Original issue date: August 17, 1995
- Last revised: August 30, 1996
- Information previously in the README was inserted
- into the advisory.
-
- A complete revision history is at the end of this file.
-
- Topic: Sendmail v.5 Vulnerability
- - -----------------------------------------------------------------------------
-
- The CERT Coordination Center has received reports of a vulnerability in
- sendmail version 5. Although this version is several years old, it is still
- in use. The vulnerability enables intruders to gain unauthorized privileges,
- including root. We recommend installing all patches from your vendor or
- moving to the current version of Eric Allman's sendmail (version 8.6.12).
-
- The vulnerability is currently present in all versions of IDA sendmail and in
- some vendors' releases of sendmail. The vendors who have reported to us are
- listed in Section I.
-
- We will update this advisory as we receive additional information.
- Please check advisory files regularly for updates that relate to your site.
-
- - -----------------------------------------------------------------------------
-
- I. Description
-
- In sendmail version 5, there is a vulnerability that intruders can
- exploit to create files, append to existing files, or execute programs.
-
- The vulnerability is currently present in all versions of IDA sendmail
- and in some vendors' releases of sendmail.
-
- Many vendors have previously installed upgrades or developed patches to
- address the problem; some are working on patches now. Here is a summary
- of vendors who reported to us as of the date of this advisory.
-
- More details can be found in the appendix of this advisory, which we will
- update as we receive additional information.
-
- If you do not see your vendor's name or if you have questions about the
- version of sendmail at your site, please contact your vendor directly.
-
- Source or Vendor
- ----------------
- Eric Allman
- Apple Computer, Inc.
- Berkeley SW. Design
- Cray Research, Inc.
- Data General Corp.
- Digital Equipment Corp.
- Harris Computer Systems
- Hewlett-Packard Company
- IBM Corporation
-
- NEC Corporation
- NeXT Computer, Inc.
- Open Software Foundation
- The Santa Cruz Operation
- Silicon Graphics Inc.
- Solbourne (Grumman)
- Sun Microsystems, Inc.
-
- Freely available and distributable software:
- Users of the freely available operating systems Linux (systems using
- sendmail rather than smail), NetBSD, and FreeBSD should upgrade to
- sendmail 8.6.12.
-
- II. Impact
-
- Local and remote users can create files, append to existing files or run
- programs on the system. Exploitation can lead to root access.
-
- III. Solution
-
- A. What to do
-
- IDA users: Convert to sendmail 8.6.12.
-
- Other users: Check the vendor information in the appendix of this
- advisory.
-
- Ensure that you have kept current with upgrades and patches from
- your vendor.
-
- If no patch is currently available, an alternative is to
- install sendmail 8.6.12.
-
-
- B. What you need to know about sendmail
-
- 1. Location
- Sendmail is available by anonymous FTP from
-
- ftp://ftp.cs.berkeley.edu/ucb/sendmail
- ftp://info.cert.org/pub/tools/sendmail/sendmail.8.6.12
- ftp://ftp.auscert.org.au/pub/mirrors/ftp.cs.berkeley.edu/ucb/sendmail
- ftp://ftp.cert.dfn.de/pub/tools/net/sendmail/
-
- The checksums are
-
- MD5 (sendmail.8.6.12.base.tar.Z) = 31591dfb0dacbe0a7e06147747a6ccea
- MD5 (sendmail.8.6.12.cf.tar.Z) = c60becd7628fad715df8f7e13dcf3cc6
- MD5 (sendmail.8.6.12.misc.tar.Z) = 6212390ca0bb4b353e29521f1aab492f
- MD5 (sendmail.8.6.12.patch) = 10961687c087ef30920b13185eef41e8
- MD5 (sendmail.8.6.12.xdoc.tar.Z) = 8b2252943f365f303b6302b71ef9a841
-
-
- 2. Additional security
-
- To restrict sendmail's program mailer facility, obtain
- and install the sendmail restricted shell program (smrsh)
- by Eric Allman (the original author of sendmail), following the
- directions included with the program.
-
- You should run smrsh with any UNIX system that is running sendmail,
- regardless of vendor or version. Even with Eric Allman's sendmail
- version 8.6.12, it is necessary for security-conscious sites to use
- the smrsh program, as this carries out preprocessing of mail
- headers and adds an extra layer of defense by controlling what
- programs can be spawned by the incoming mail message. Note that
- smrsh has now been included as part of the sendmail distribution
- (effective with 8.7).
-
- We also urge you to ensure that all patches are installed for the
- distribution of sendmail you are using. Regardless of the vendor or
- version of your UNIX systems and sendmail, the general advice to
- "run the smrsh tool in conjunction with the most recently patched
- version of sendmail for your system" holds true.
-
- Copies of smrsh may be obtained via anonymous FTP from
-
- ftp://info.cert.org/pub/tools/smrsh
- ftp://ftp.uu.net/pub/security/smrsh
-
- Checksum information
- --------------------
- BSD Sum
- 30114 5 README
- 25757 2 smrsh.8
- 46786 5 smrsh.c
-
- System V Sum
- 56478 10 README
- 42281 4 smrsh.8
- 65517 9 smrsh.c
-
- MD5 Checksum
- MD5 (README) = fc4cf266288511099e44b664806a5594
- MD5 (smrsh.8) = 35aeefba9714f251a3610c7b1714e355
- MD5 (smrsh.c) = d4822ce7c273fc8b93c68e39ec67739c
-
-
- 3. Notes on installation
-
- Depending upon the currently installed sendmail program, switching
- to a different sendmail may require significant effort (such as
- rewriting the sendmail.cf file.)
-
- ...........................................................................
-
- Appendix: Vendor Information
-
- Below is information we have received from vendors about the vulnerability in
- sendmail version 5. If you do not see your vendor's name below, contact the
- vendor directly for information.
-
- - -------------
- Eric Allman
-
- Sendmail 8.6.10 and later are not vulnerable. The current version is 8.6.12.
- Because the current version addresses vulnerabilities that appear in earlier
- versions, it is a good idea to use 8.6.12.
-
- Sendmail is available by anonymous FTP from
-
- ftp://ftp.cs.berkeley.edu/ucb/sendmail
- ftp://info.cert.org/pub/tools/sendmail/sendmail.8.6.12
- ftp://ftp.auscert.org.au/pub/mirrors/ftp.cs.berkeley.edu/ucb/sendmail
- ftp://ftp.cert.dfn.de/pub/tools/net/sendmail/
-
- The checksums are
-
- MD5 (sendmail.8.6.12.base.tar.Z) = 31591dfb0dacbe0a7e06147747a6ccea
- MD5 (sendmail.8.6.12.cf.tar.Z) = c60becd7628fad715df8f7e13dcf3cc6
- MD5 (sendmail.8.6.12.misc.tar.Z) = 6212390ca0bb4b353e29521f1aab492f
- MD5 (sendmail.8.6.12.patch) = 10961687c087ef30920b13185eef41e8
- MD5 (sendmail.8.6.12.xdoc.tar.Z) = 8b2252943f365f303b6302b71ef9a841
-
- - -------------
- Apple Computer, Inc.
-
- [The following information also appeared in CERT advisory
- CA-95:05, "Sendmail Vulnerabilities."]
-
- An upgrade to A/UX version 3.1 (and 3.1.1) for these vulnerabilities is
- available. The upgrade replaces the sendmail binary with the 8.6.10
- version. It is available via anonymous FTP from ftp.support.apple.:
-
- pub/apple_sw_updates/US/Unix/A_UX/supported/3.x/sendmail/
-
- It is also available via anonymous FTP from abs.apple.com:
-
- pub/abs/aws95/patches/sendmail/
-
- In both cases the compressed binary has the following signature:
-
- MD5 (sendmail.Z) = 31bb15604517630f46d7444a6cfab3f1
-
- Uncompress(1) this file and replace the existing version in /usr/lib;
- be sure to preserve the hard links to /usr/ucb/newaliases and
- /usr/ucb/mailq, kill the running sendmail and restart.
-
- Earlier versions of A/UX are not supported by this patch. Users of
- previous versions are encouraged to update their system or compile
- the latest version of sendmail available from ftp.cs.berkeley.edu.
-
- Customers should contact their reseller for any additional information.
-
- - -------------
- Berkeley Software Design, Inc. (BSDI)
-
- BSD/OS V2.0.1 is not vulnerable.
-
- BSD/OS V2.0 users should install patch U200-011, available from
- ftp.bsdi.com in bsdi/patches/U200-011.
-
- BSDI Support contact information:
- Phone: +1 719 536 9346
- EMail: support@bsdi.com
-
- - -------------
- Cray Research, Inc.
- not vulnerable
-
- - -------------
- Data General Corporation
-
- DG/UX 5.4R3.00 and 5.4R3.10 (and associated Trusted version) are
- vulnerable. Patches in progress now.
-
- The upcoming release (R4.10 and R4.11) will not have this vulnerability
- since these releases ship sendmail version 8.
-
- - -------------
- Digital Equipment Corp.
-
- A patch for SENDMAIL (ULTSENDMAIL_EO1044 & OSFSENDMAIL_E01032) has been
- available for some time, so if you have kept current with patches you are not
- vulnerable to this particular reported problem.
-
- If you have not applied the kits above, Digital Equipment Corporation strongly
- urges customers to upgrade to the latest versions of ULTRIX V4.4 or DIGITAL
- DEC OSF/1 V3.2, then apply the appropriate sendmail solution kit.
-
- The above kits can be obtained through your normal Digital support channels or
- by access (kit) request via DSNlink, DSIN, or DIA.
-
- - -------------
- Grumman Systems Support Corporation (GSSC)
-
- GSSC now performs all Solbourne software and hardware support.
-
- We recommend running sendmail 8.6.10 (or later revision.)
- 8.6.12 has proven reliable in production use on Solbourne systems.
-
- We plan to release the Solbourne version of the Sun patch
- when it becomes available.
-
- Contact info:
-
- ftp: ftp.nts.gssc.com
- phone: 1-800-447-2861
- email: support@nts.gssc.com
-
- - -------------
- Harris Computer Systems
- not vulnerable
-
- - -------------
- Hewlett-Packard Company
-
- Hewlett-Packard issued security bulletin #25 on April 2, 1995 announcing
- patches and describing a fix. The patches are
-
- PHNE_5402 (series 700/800, HP-UX 9.x), or
- PHNE_5401 (series 700/800, HP-UX 8.x), or
- PHNE_5384 (series 300/400, HP-UX 9.x), or
- PHNE_5383 (series 300/400, HP-UX 8.x), or
- PHNE_5387 (series 700, HP-UX 9.09), or
- PHNE_5388 (series 700, HP-UX 9.09+), or
- PHNE_5389 (series 800, HP-UX 9.08)
-
- The bulletin is available from the HP SupportLine and from http://www.hp.com
- in the HPSL category and from http://support.mayfield.hp.com.
-
- Patches may be obtained from HP via FTP (this is NOT anonymous FTP) or the HP
- SupportLine. To obtain HP security patches, you must first register with the
- HP SupportLine. The registration instructions are available via anonymous FTP
- at info.cert.org in the file "pub/vendors/hp/supportline_and_patch_retrieval".
-
- HP SupportLine: 1-415-691-3888
- phone: 1-415-691-3680
- telnet/ftp: support.mayfield.hp.com
- WWW: http://www.hp.com
- http://support.mayfield.hp.com.
-
- - -------------
- IBM Corporation
-
- A patch (ptf U425863) has been available for AIX 3.2 for some time.
- To determine if you have this ptf on your system, run the following command:
- % lslpp -lB U425863
-
- If you have not already applied the patch, you can order it from IBM as APAR
- ix40304 To order APARs from IBM in the U.S., call 1-800-237-5511. To obtain
- APARs outside of the U.S., contact your local IBM representative.
-
- - -------------
- NEC Corporation
-
- OS Version Status
- - ------------------ ------------ ------------------------------
- EWS-UX/V(Rel4.0) R1.x - R6.x vulnerable
-
- EWS-UX/V(Rel4.2) R7.x - R10.x vulnerable
- patch available
-
- EWS-UX/V(Rel4.2MP) R10.x vulnerable
- patch available
-
- UP-UX/V R1.x - R4.x vulnerable
-
- UP-UX/V(Rel4.2MP) R5.x - R7.2 vulnerable
- patch available except for R5.x
-
- UX/4800 R11.x not vulnerable
-
-
- Contacts for further information:
- e-mail:UXcert-CT@d2.bsd.nes.nec.co.jp
-
- - -------------
- NeXT Computer, Inc.
-
- The sendmail executables included with all versions of NEXTSTEP up
- to and including release 3.3 are vulnerable to this problem. The
- SendmailPatch previously released for NEXTSTEP 3.1 and 3.2 is also
- vulnerable.
-
- An updated patch is planned which will address this vulnerability.
- The availability of this patch will be indicated in the NeXTanswers
- section of http://www.next.com/. For further information you may
- contact NeXT's Technical Support Hotline at (+1-800-955-NeXT) or
- via email to ask_next@NeXT.com.
-
- - -------------
- Open Software Foundation
- not vulnerable
-
- - -------------
- The Santa Cruz Operation
-
- Support Level Supplement (SLS) net382e, contains a patched version of
- sendmail for the following releases:
-
- SCO TCP/IP Runtime System Release 1.2.1
- SCO Open Desktop Lite Release 3.0
- SCO Open Desktop Release 3.0
- SCO Open Server Network System Release 3.0
- SCO Open Server Enterprise System Release 3.0
-
- SCO OpenServer 5 contains Sendmail version 8.6.8, and contains fixes
- to all problems reported in this and previous sendmail advisories.
- Users of previous releases should consider updating.
-
- NOTE: The MMDF (M)ulti-Channel (M)emorandum (D)istribution
- (F)acility is the default mail system on SCO systems. The MMDF mail
- system is not affected by any of the problems mentioned in these
- advisories. Administrators who wish to use sendmail must specifically
- configure the system to do so during or after installation.
-
- To acquire SLS net382e:
-
- Anonymous ftp on the Internet:
- ==============================
-
- ftp://ftp.sco.COM/SLS/net382e.Z (disk image)
- ftp://ftp.sco.COM/SLS/net382e.ltr.Z (documentation)
-
- Anonymous uucp:
- ===============
-
- United States:
- - --------------
- sosco!/usr/spool/uucppublic/SLS/net382e.Z (disk image)
- sosco!/usr/spool/uucppublic/SLS/net382e.ltr.Z (documentation)
-
- United Kingdom:
- - ---------------
- scolon!/usr/spool/uucppublic/SLS/net382e.Z (disk image)
- scolon!/usr/spool/uucppublic/SLS/net382e.ltr.Z (documentation)
-
-
- The telephone numbers and login names for the machines sosco and scolon
- are provided with the default /usr/lib/uucp/Systems file shipped with
- every SCO system.
-
- The checksums for the files listed above are as follows:
-
- file sum -r md5
- =========================== ================================
- net382e.Z: 29715 1813 41efeaaa855e4716ed70c12018014092
- net382e.ltr.Z 52213 14 287ba6131519cba351bc58cb32880fda
-
-
- The Support Level Supplement is also available on floppy media from SCO
- Support at the following telephone numbers:
-
- USA/Canada: 6am-5pm Pacific Daylight Time (PDT)
- -----------
- 1-408-425-4726 (voice)
- 1-408-427-5443 (fax)
-
- Pacific Rim, Asia, and Latin American customers: 6am-5pm Pacific
- ------------------------------------------------ Daylight Time
- (PDT)
- 1-408-425-4726 (voice)
- 1-408-427-5443 (fax)
-
- Europe, Middle East, Africa: 9am-5:00pm Greenwich Mean Time (GMT)
- ----------------------------
- +44 1923 816344 (voice)
- +44 1923 817781 (fax)
-
- For further information, contact SCO at one of the above numbers,
- send electronic mail to support@sco.COM, or see the SCO Web Page at:
- http://www.sco.COM.
-
- - -------------
- Silicon Graphics Inc.
-
- On February 22, 1995, Silicon Graphics issued security advisory 19950201
- addressing sendmail issues being raised at the time and previous older
- version sendmail issues. Patches are still available and as part of these
- patches, sendmail version 8.6.12 is provided as standard. At the time
- of this writing here is the patch information.
-
- **** IRIX 3.x ****
-
- Unfortunately, Silicon Graphics Inc, no longer supports the IRIX 3.x
- operating system and therefore has no patches or binaries to provide.
-
- However, two possible actions still remain: 1) upgrade the system to a
- supported version of IRIX (see below) and then install the binary/patch
- or 2) obtain the sendmail source code from anonymous FTP at
- ftp.cs.berkeley.edu and compile the program manually.
-
- **** IRIX 4.x ****
-
- For the IRIX operating system version 4.x, a manually installable
- binary replacement has been generated and made available via anonymous
- ftp and/or your service/support provider. The binary is sendmail.new.Z
- and is installable on all 4.x platforms.
-
- Binaries can be found at ftp://ftp.sgi.com/ftp/Patches/4.x
- but not at the alternative location, ~ftp/Security.
-
- ##### Checksums as of August 17, 1995, 5 p.m. EDT ####
-
- Filename: sendmail.new.Z
- Algorithm #1 (sum -r): 30749 422 sendmail.new.Z
- Algorithm #2 (sum): 62511 422 sendmail.new.Z
-
- MD5 checksum: AB327D85D40085D74E9C230EB1A002C3
-
-
- Note: SGI plans to upgrade the IRIX 4.x patch soon. If there is a difference
- between the checksums of the file you obtain and those reported here, you
- should rely on SGI's <sendmail-filename>.pgp.and.chksums file.
-
- After obtaining the binary, it may be installed with the instructions
- below:
-
- 1) Become the root user on the system.
-
- % /bin/su -
- Password:
- #
-
- 2) Stop the current mail processes.
-
- # /etc/init.d/mail stop
-
- 3) Rename the current sendmail binary to a temporary
- name.
-
- # mv /usr/lib/sendmail /usr/lib/sendmail.stock
-
- 4) Change permissions on the old sendmail binary so it can not
- be used anymore.
-
- # chmod 0400 /usr/lib/sendmail.stock
-
- 5) Uncompress the binary.
-
- # uncompress /tmp/sendmail.new.Z
-
- 6) Put the new sendmail binary into place (in the example
- here the binary was retrieved via anonymous ftp and put
- in /tmp)
-
- # mv /tmp/sendmail.new /usr/lib/sendmail
-
- 7) Insure the correct permissions and ownership on the new
- sendmail.
-
- # chown root.sys /usr/lib/sendmail
- # chmod 4755 /usr/lib/sendmail
-
- 8) Restart the mail system with the new sendmail binary in place.
-
- # /etc/init.d/mail start
-
- 9) Return to normal user level.
-
- # exit
-
- **** IRIX 5.0.x, 5.1.x ****
-
- For the IRIX operating systems versions 5.0.x, 5.1.x, an upgrade
- to 5.2 or better is required first. When the upgrade is completed,
- then the patch described in the next section "**** IRIX 5.2, 5.3, 6.0,
- 6.0.1 ***" can be applied.
-
- **** IRIX 5.2, 5.3, 6.0, 6.0.1 ****
-
- For the IRIX operating system versions 5.2, 5.3, 6.0 and 6.0.1, an
- inst-able patch has been generated and made available via anonymous
- ftp and/or your service/support provider. The patch is number 332
- and will install on IRIX 5.2, 5.3, 6.0 and 6.0.1 .
-
- The SGI anonymous ftp site is ftp.sgi.com (192.48.153.1). Patch
- 332 can be found in the following directories on the ftp server:
-
- ~ftp/Security
- or
- ~ftp/Patches/5.2
- ~ftp/Patches/5.3
- ~ftp/Patches/6.0
- ~ftp/Patches/6.0.1
-
- For obtaining security information, patches or assistance, please
- contact your SGI support provider.
-
- If there are questions about this patch information, email can be
- sent to cse-security-alert@csd.sgi.com .
-
- For reporting new SGI security issues, email can be sent to
- security-alert@sgi.com .
-
- - -------------
- Solbourne
- see Grumman Systems Support Corporation
-
- - -------------
- Sun Microsystems, Inc.
-
- Solaris 2.x is not vulnerable.
-
- Sun OS 4.1.3, 4.1.37_u1, and 4.1.4 are vulnerable, and a patch will be
- available soon.
-
- This patch can be obtained from local Sun Answer Centers and through anonymous
- FTP from ftp.uu.net in the /systems/sun/sun-dist directory. In Europe, the
- patch is available from mcsun.eu.net (192.16.202.1) in the /sun/fixes
- directory.
-
-
- - ---------------------------------------------------------------------------
- The CERT Coordination Center staff thanks the vendors listed in this
- advisory, along with Karl Strickland and Neil Woods for their support
- in the development of this advisory.
- - ---------------------------------------------------------------------------
-
- If you believe that your system has been compromised, contact the CERT
- Coordination Center or your representative in the Forum of Incident
- Response and Security Teams (FIRST).
-
- If you wish to send sensitive incident or vulnerability information to
- CERT staff by electronic mail, we strongly advise that the email be
- encrypted. The CERT Coordination Center can support a shared DES key, PGP
- (public key available via anonymous FTP on info.cert.org), or PEM (contact
- CERT staff for details).
-
- Internet email: cert@cert.org
- Telephone: +1 412-268-7090 (24-hour hotline)
- CERT personnel answer 8:30 a.m.-5:00 p.m. EST(GMT-5)/EDT(GMT-4),
- and are on call for emergencies during other hours.
- Fax: +1 412-268-6989
-
- Postal address: CERT Coordination Center
- Software Engineering Institute
- Carnegie Mellon University
- Pittsburgh, PA 15213-3890
- USA
-
- CERT advisories and bulletins are posted on the USENET newsgroup
- comp.security.announce. If you would like to have future advisories and
- bulletins mailed to you or to a mail exploder at your site, please send mail
- to cert-advisory-request@cert.org.
-
- Past advisories, CERT bulletins, information about FIRST representatives, and
- other information related to computer security are available for anonymous
- FTP from info.cert.org.
-
-
- Copyright 1995, 1996 Carnegie Mellon University
- This material may be reproduced and distributed without permission provided it
- is used for noncommercial purposes and the copyright statement is included.
-
- CERT is a service mark of Carnegie Mellon University.
-
- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
- Revision history
-
- Aug. 07, 1996 Information previously in the README was inserted
- into the advisory.
- Nov. 07, 1995 Sec. III.B.2 - emphasized that smrsh should be run with all
- versions of sendmail.
- Sep. 20, 1995 Sec. I - changed "public domain" to "freely available."
- Appendix - added an entry for Data General.
- Aug. 21, 1995 Sec. III.B and appendix, Eric Allman - added a German FTP site
- for sendmail and corrected the URL for Australia.
- Appendix, Silicon Graphics - corrected information for 4.x
- Appendix, Sun - corrected a typo in the OS number
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