Updated sendmail packages fix critical security issues

Updated Sendmail packages are available to fix a vulnerability that
may allow remote attackers to gain root privileges by sending a
carefully crafted message.

These packages also fix a security bug if sendmail is configured to use smrsh.

Sendmail is a widely used Mail Transport Agent (MTA) which is included
in all Red Hat Linux distributions.

During a code audit of Sendmail by ISS, a critical vulnerability was
uncovered that affects unpatched versions of Sendmail prior to version
8.12.8. A remote attacker can send a carefully crafted email message
which, when processed by sendmail, causes arbitrary code to be
executed as root.

We are advised that a proof-of-concept exploit is known to exist, but
is not believed to be in the wild.

Since this is a message-based vulnerability, MTAs other than Sendmail
may pass on the carefully crafted message. This means that unpatched
versions of Sendmail inside a network could still be at risk even if
they do not accept external connections directly.

In addition, the restricted shell (SMRSH) in Sendmail allows attackers to
bypass the intended restrictions of smrsh by inserting additional commands
after "||" sequences or "/" characters, which are not properly filtered or
verified. A sucessful attack would allow an attacker who has a local
account on a system which has explicitly enabled smrsh to execute arbitrary
binaries as themselves by utilizing their .forward file.

All users are advised to update to these erratum packages. For Red Hat
Linux 8.0 we have included Sendmail version 8.12.8 which is not vulnerable
to these issues. For all other distributions we have included a backported
patch which corrects these vulnerabilities.

Red Hat would like to thank Eric Allman for his assistance with this
vulnerability.

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

To update all RPMs for your particular architecture, run:

rpm -Fvh [filenames]

where [filenames] is a list of the RPMs you wish to upgrade. Only those
RPMs which are currently installed will be updated. Those RPMs which are
not installed but included in the list will not be updated. Note that you
can also use wildcards (*.rpm) if your current directory *only* contains the
desired RPMs.

Please note that this update is also available via Red Hat Network. Many
people find this an easier way to apply updates. To use Red Hat Network,
launch the Red Hat Update Agent with the following command:

up2date

This will start an interactive process that will result in the appropriate
RPMs being upgraded on your system.

https://www.redhat.com/security/data/cve/CVE-2002-1165.html
https://www.redhat.com/security/data/cve/CVE-2002-1337.html
http://www.cert.org/advisories/CA-2003-07.html
http://marc.theaimsgroup.com/?l=bugtraq&m=103350914307274

bug, security, sendmail, smrsh