Fwd: CERT Advisory CA-2003-12 Buffer Overflow in Sendmail

Ewald Beekman E.H.Beekman at AMC.UVA.NL
Sun Mar 30 20:37:08 IST 2003


Saw on rpmfind.net that the Polish Linux Distro also had a rpm
out for the new 8.12.9
ftp://fr2.rpmfind.net/linux/PLD/dists/ra/updates/security/i686/sendmail-8.12.9-1.i686.rpm

With a little tweaking you can run that binary on RH-8,
you also have to install db3.1 from RH-7.2 and add two links:
[~]# cd /lib
[/lib]# ln -s libcrypto.so.0.9.6b libcrypto.so.0.9.6.1
[/lib]# ln -s libssl.so.0.9.6b libssl.so.0.9.6.1

But if you are using certain features with your sendmail config
you might run into trouble because the PLD version has less options
compiled in:

[]# /usr/sbin/sendmail-8.12.9 -d0.1 < /dev/null
Version 8.12.9
 Compiled with: DNSMAP LDAPMAP LOG MATCHGECOS MIME7TO8 MIME8TO7
                NAMED_BIND NETINET NETINET6 NETUNIX NEWDB NIS PIPELINING SASL
                SCANF STARTTLS USERDB USE_LDAP_INIT

[]# /usr/sbin/sendmail.sendmail  -d0.1 < /dev/null
Version 8.12.8
 Compiled with: DNSMAP HESIOD HES_GETMAILHOST LDAPMAP LOG MAP_REGEX
                MATCHGECOS MILTER MIME7TO8 MIME8TO7 NAMED_BIND NETINET NETINET6
                NETUNIX NEWDB NIS PIPELINING SASL SCANF STARTTLS TCPWRAPPERS
                USERDB USE_LDAP_INIT

Ewald...

On Sat, Mar 29, 2003 at 06:28:04PM -0800, Craig Pratt wrote:
> Yes, it's time to patch sendmail again.
>
> The only distro at this time with the new version (8.12.9) or patch is
> slackware, AFAIK.
>
> Why does this always happen on the weekend?
>
> Craig
>
> ---
> Craig Pratt
> Strongbox Network Services Inc.
> mailto:craig at strong-box.net
>
> Begin forwarded message:
> >From: CERT Advisory <cert-advisory at cert.org>
> >Date: Sat Mar 29, 2003  11:57:59  AM US/Pacific
> >To: cert-advisory at cert.org
> >Subject: CERT Advisory CA-2003-12 Buffer Overflow in Sendmail
> >X-Mailscanner-Spamcheck: not spam, SpamAssassin (score=1.4, required
> >4, AWL, FROM_AND_TO_SAME_5, LINES_OF_YELLING, NOSPAM_INC,
> >PGP_SIGNATURE, SPAM_PHRASE_02_03)
> >X-Mailscanner-Spamscore: s
> >
> >
> >
> >-----BEGIN PGP SIGNED MESSAGE-----
> >
> >CERT Advisory CA-2003-12 Buffer Overflow in Sendmail
> >
> >   Original release date: March 29, 2003
> >   Last revised:
> >   Source: CERT/CC
> >
> >   A complete revision history can be found at the end of this file.
> >
> >Systems Affected
> >
> >     * Sendmail Pro (all versions)
> >     * Sendmail Switch 2.1 prior to 2.1.6
> >     * Sendmail Switch 2.2 prior to 2.2.6
> >     * Sendmail Switch 3.0 prior to 3.0.4
> >     * Sendmail for NT 2.X prior to 2.6.3
> >     * Sendmail for NT 3.0 prior to 3.0.4
> >     * Systems  running  open-source  sendmail  versions prior to
> >8.12.9,
> >       including UNIX and Linux systems
> >
> >Overview
> >
> >   There  is a vulnerability in sendmail that can be exploited to
> >cause a
> >   denial-of-service  condition  and  could  allow  a  remote attacker
> >to
> >   execute  arbitrary  code  with  the privileges of the sendmail
> >daemon,
> >   typically root.
> >
> >I. Description
> >
> >   There  is  a remotely exploitable vulnerability in sendmail that
> >could
> >   allow  an  attacker  to  gain control of a vulnerable sendmail
> >server.
> >   Address  parsing code in sendmail does not adequately check the
> >length
> >   of  email addresses. An email message with a specially crafted
> >address
> >   could  trigger  a stack overflow. This vulnerability was discovered
> >by
> >   Michal Zalewski.
> >
> >   This vulnerability is different than the one described in
> >CA-2003-07.
> >
> >   Most  organizations  have  a variety of mail transfer agents (MTAs)
> >at
> >   various  locations  within their network, with at least one exposed
> >to
> >   the   Internet.   Since   sendmail  is  the  most  popular  MTA,
> >most
> >   medium-sized  to  large  organizations are likely to have at least
> >one
> >   vulnerable   sendmail   server.  In  addition,  many  UNIX  and
> >Linux
> >   workstations  provide  a  sendmail  implementation that is enabled
> >and
> >   running by default.
> >
> >   This    vulnerability    is    message-oriented    as    opposed
> >to
> >   connection-oriented. That means that the vulnerability is triggered
> >by
> >   the  contents  of  a  specially-crafted  email  message rather than
> >by
> >   lower-level  network  traffic.  This  is important because an MTA
> >that
> >   does  not  contain  the  vulnerability will pass the malicious
> >message
> >   along  to  other  MTAs  that may be protected at the network level.
> >In
> >   other  words, vulnerable sendmail servers on the interior of a
> >network
> >   are  still  at risk, even if the site's border MTA uses software
> >other
> >   than sendmail. Also, messages capable of exploiting this
> >vulnerability
> >   may pass undetected through many common packet filters or firewalls.
> >
> >   This   vulnerability  has  been  successfully  exploited  to  cause
> > a
> >   denial-of-service   condition  in  a  laboratory  environment.  It
> >is
> >   possible that this vulnerability could be used to execute code on
> >some
> >   vulnerable systems.
> >
> >   The CERT/CC is tracking this issue as VU#897604. This reference
> >number
> >   corresponds to CVE candidate CAN-2003-0161.
> >
> >   For more information, please see
> >
> >          http://www.sendmail.org
> >          http://www.sendmail.org/8.12.9.html
> >          http://www.sendmail.com/security/
> >
> >   For  the  latest  information  about this vulnerability, including
> >the
> >   most recent vendor information, please see
> >
> >          http://www.kb.cert.org/vuls/id/897604
> >
> >   This vulnerability is distinct from VU#398025.
> >
> >II. Impact
> >
> >   Successful   exploitation   of   this   vulnerability   may   cause
> > a
> >   denial-of-service   condition   or  allow  an  attacker  to  gain
> >the
> >   privileges  of  the  sendmail  daemon, typically root. Even
> >vulnerable
> >   sendmail  servers  on  the  interior of a given network may be at
> >risk
> >   since  the  vulnerability  is triggered by the contents of a
> >malicious
> >   email message.
> >
> >III. Solution
> >
> >Apply a patch from Sendmail, Inc.
> >
> >   Sendmail  has produced patches for versions 8.9, 8.10, 8.11, and
> >8.12.
> >   However,  the  vulnerability  also  exists  in earlier versions of
> >the
> >   code;  therefore,  site  administrators  using  an earlier version
> >are
> >   encouraged  to upgrade to 8.12.9. These patches, and a signature
> >file,
> >   are located at
> >
> >          ftp://ftp.sendmail.org/pub/sendmail/prescan.tar.gz.uu
> >          ftp://ftp.sendmail.org/pub/sendmail/prescan.tar.gz.uu.asc
> >
> >Apply a patch from your vendor
> >
> >   Many  vendors  include  vulnerable  sendmail  servers as part of
> >their
> >   software distributions. We have notified vendors of this
> >vulnerability
> >   and  recorded  the  statements  they  provided  in  Appendix A of
> >this
> >   advisory.  The  most  recent  vendor  information  can be found in
> >the
> >   systems affected section of VU#897604.
> >
> >Enable the RunAsUser option
> >
> >   There is no known workaround for this vulnerability. Until a patch
> >can
> >   be  applied,  you  may  wish to set the RunAsUser option to reduce
> >the
> >   impact  of this vulnerability. As a good general practice, the
> >CERT/CC
> >   recommends  limiting  the  privileges  of  an  application  or
> >service
> >   whenever possible.
> >
> >Appendix A. - Vendor Information
> >
> >   This  appendix  contains  information  provided  by  vendors  for
> >this
> >   advisory.  As  vendors  report new information to the CERT/CC, we
> >will
> >   update this section and note the changes in our revision history.
> >If a
> >   particular  vendor  is  not  listed  below, we have not received
> >their
> >   comments.
> >
> >Red Hat Inc.
> >
> >   Red  Hat  distributes  sendmail in all Red Hat Linux distributions.
> >We
> >   are  currently [Mar29] working on producing errata packages to
> >correct
> >   this  issue,  when  complete  these  will  be available along with
> >our
> >   advisory  at  the  URL  below.  At  the same time users of the Red
> >Hat
> >   Network will be able to update their systems using the 'up2date'
> >tool.
> >
> >   Red Hat Linux:
> >
> >          http://rhn.redhat.com/errata/RHSA-2003-120.html
> >
> >   Red Hat Enterprise Linux:
> >
> >          http://rhn.redhat.com/errata/RHSA-2003-121.html
> >
> >The Sendmail Consortium
> >
> >   The  Sendmail  Consortium  recommends  that  sites  upgrade  to
> >8.12.9
> >   whenever possible. Alternatively, patches are available for 8.9,
> >8.10,
> >   8.11, and 8.12 on http://www.sendmail.org/.
> >
> >Sendmail, Inc.
> >
> >   All  commercial  releases including Sendmail Switch, Sendmail
> >Advanced
> >   Message  Server (which includes the Sendmail Switch MTA), Sendmail
> >for
> >   NT,  and Sendmail Pro are affected by this issue. Patch information
> >is
> >   available at http://www.sendmail.com/security/.
> >     _________________________________________________________________
> >
> >   Our  thanks  to  Eric  Allman,  Claus  Assmann, Greg Shapiro, and
> >Dave
> >   Anderson  of  Sendmail  for  reporting  this  problem  and  for
> >their
> >   assistance in coordinating the response to this problem. We also
> >thank
> >   Michal Zalewski for discovering this vulnerability.
> >     _________________________________________________________________
> >
> >   Authors: Art Manion and Shawn V. Hernan
> >
> >______________________________________________________________________
> >
> >   This document is available from:
> >   http://www.cert.org/advisories/CA-2003-12.html
> >
> >______________________________________________________________________
> >
> >CERT/CC Contact Information
> >
> >   Email: cert at cert.org
> >          Phone: +1 412-268-7090 (24-hour hotline)
> >          Fax: +1 412-268-6989
> >          Postal address:
> >          CERT Coordination Center
> >          Software Engineering Institute
> >          Carnegie Mellon University
> >          Pittsburgh PA 15213-3890
> >          U.S.A.
> >
> >   CERT/CC   personnel   answer  the  hotline  08:00-17:00  EST(GMT-5)
> > /
> >   EDT(GMT-4)  Monday  through  Friday;  they are on call for
> >emergencies
> >   during other hours, on U.S. holidays, and on weekends.
> >
> >Using encryption
> >
> >   We  strongly  urge you to encrypt sensitive information sent by
> >email.
> >   Our public PGP key is available from
> >   http://www.cert.org/CERT_PGP.key
> >
> >   If  you  prefer  to  use  DES,  please  call the CERT hotline for
> >more
> >   information.
> >
> >Getting security information
> >
> >   CERT  publications  and  other security information are available
> >from
> >   our web site
> >   http://www.cert.org/
> >
> >   To  subscribe  to  the CERT mailing list for advisories and
> >bulletins,
> >   send  email  to majordomo at cert.org. Please include in the body of
> >your
> >   message
> >
> >   subscribe cert-advisory
> >
> >   *  "CERT"  and  "CERT  Coordination Center" are registered in the
> >U.S.
> >   Patent and Trademark Office.
> >
> >______________________________________________________________________
> >
> >   NO WARRANTY
> >   Any  material furnished by Carnegie Mellon University and the
> >Software
> >   Engineering  Institute  is  furnished  on  an  "as is" basis.
> >Carnegie
> >   Mellon University makes no warranties of any kind, either expressed
> >or
> >   implied  as  to  any matter including, but not limited to, warranty
> >of
> >   fitness  for  a  particular purpose or merchantability, exclusivity
> >or
> >   results  obtained from use of the material. Carnegie Mellon
> >University
> >   does  not  make  any warranty of any kind with respect to freedom
> >from
> >   patent, trademark, or copyright infringement.
> >     _________________________________________________________________
> >
> >   Conditions for use, disclaimers, and sponsorship information
> >
> >   Copyright 2003 Carnegie Mellon University.
> >   Revision History
> >
> >   March 29,2003: Initial release
> >
> >-----BEGIN PGP SIGNATURE-----
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> >
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>
>
> --
> This message checked for dangerous content by MailScanner on StrongBox.

--
Ewald Beekman, Security Engineer, Academic Medical Center,
dept. ADB/ICT Computer & Network Services, The Netherlands
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This fortune is false.



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