Fwd: CERT Advisory CA-2003-12 Buffer Overflow in Sendmail
Craig Pratt
craig at STRONG-BOX.NET
Sun Mar 30 03:28:04 IST 2003
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
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> -----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.
>
> ______________________________________________________________________
>
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> Any material furnished by Carnegie Mellon University and the
> Software
> Engineering Institute is furnished on an "as is" basis.
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> _________________________________________________________________
>
> Conditions for use, disclaimers, and sponsorship information
>
> Copyright 2003 Carnegie Mellon University.
> Revision History
>
> March 29,2003: Initial release
>
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