RHSA-2010:0237 - Security Advisory

Topic

Updated sendmail packages that fix two security issues and several bugs are
now available for Red Hat Enterprise Linux 5.

The Red Hat Security Response Team has rated this update as having low
security impact. Common Vulnerability Scoring System (CVSS) base scores,
which give detailed severity ratings, are available for each vulnerability
from the CVE links in the References section.

Description

Sendmail is a very widely used Mail Transport Agent (MTA). MTAs deliver
mail from one machine to another. Sendmail is not a client program, but
rather a behind-the-scenes daemon that moves email over networks or the
Internet to its final destination.

The configuration of sendmail in Red Hat Enterprise Linux was found to not
reject the "localhost.localdomain" domain name for email messages that come
from external hosts. This could allow remote attackers to disguise spoofed
messages. (CVE-2006-7176)

A flaw was found in the way sendmail handled NUL characters in the
CommonName field of X.509 certificates. An attacker able to get a
carefully-crafted certificate signed by a trusted Certificate Authority
could trick sendmail into accepting it by mistake, allowing the attacker to
perform a man-in-the-middle attack or bypass intended client certificate
authentication. (CVE-2009-4565)

Note: The CVE-2009-4565 issue only affected configurations using TLS with
certificate verification and CommonName checking enabled, which is not a
typical configuration.

This update also fixes the following bugs:

• sendmail was unable to parse files specified by the ServiceSwitchFile

option which used a colon as a separator. (BZ#512871)

• sendmail incorrectly returned a zero exit code when free space was low.

(BZ#299951)

• the sendmail manual page had a blank space between the -qG option and

parameter. (BZ#250552)

• the comments in the sendmail.mc file specified the wrong path to SSL

certificates. (BZ#244012)

• the sendmail packages did not provide the MTA capability. (BZ#494408)

All users of sendmail are advised to upgrade to these updated packages,
which resolve these issues.

Solution

Before applying this update, make sure all previously-released errata
relevant to your system have been applied.

This update is available via the Red Hat Network. Details on how to
use the Red Hat Network to apply this update are available at
http://kbase.redhat.com/faq/docs/DOC-11259

Affected Products

• Red Hat Enterprise Linux Server 5 x86_64
• Red Hat Enterprise Linux Server 5 ia64
• Red Hat Enterprise Linux Server 5 i386
• Red Hat Enterprise Linux Workstation 5 x86_64
• Red Hat Enterprise Linux Workstation 5 i386
• Red Hat Enterprise Linux Desktop 5 x86_64
• Red Hat Enterprise Linux Desktop 5 i386
• Red Hat Enterprise Linux for IBM z Systems 5 s390x
• Red Hat Enterprise Linux for Power, big endian 5 ppc
• Red Hat Enterprise Linux Server from RHUI 5 x86_64
• Red Hat Enterprise Linux Server from RHUI 5 i386

Fixes

• BZ - 238540 - CVE-2006-7176 sendmail allows external mail with from address xxx@localhost.localdomain
• BZ - 244012 - Old path to openssl used in sendmail.mc
• BZ - 250552 - the description about option '-qG name' should be modified in the manpage
• BZ - 440616 - there should be %{?dist} instead of %{dist} in the *.spec on the Release: line
• BZ - 449391 - sendmail allows external mail with from address xxx@localhost.localdomain
• BZ - 494408 - Sendmail should provide "MTA"
• BZ - 552622 - CVE-2009-4565 sendmail: incorrect verification of SSL certificate with NUL in name

CVEs

• CVE-2006-7176
• CVE-2009-4565

References

• http://www.redhat.com/security/updates/classification/#low