RHSA-2002:259 - Security Advisory

Topic

The sendmail packages shipped with Red Hat Linux Advanced Server have a
security bug if sendmail is configured to use smrsh. This security errata
release fixes the problem.

[Updated 06 Feb 2003]
Added fixed packages for Advanced Workstation 2.1

Description

SMRSH (the SendMail Restricted SHell) is a /bin/sh replacement for
Sendmail. It provides the ability to limit the set of executable programs
available to Sendmail.

A bug in the version of smrsh packaged as part of Sendmail 8.12.6 and
8.11.6 allows attackers to bypass shrsh's intended restrictions. This
can be done by inserting additional commands after "||" or "/" characters,
which are not properly filtered or verified. A sucessful attack would
allow an attacker who has a local account on a system to execute arbitrary
binaries as themselves by utilizing their .forward file.

Because sendmail as shipped with Red Hat Linux Advanced Server is not
configured to use smrsh, this issue only affects users who have customized
their sendmail configuration to use smrsh.

Users who have configured sendmail to use smrsh should update to these
errata packages which contain a backported security fix, and are therefore
not vulnerable to this issue.

Solution

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

Please note that this update is available via Red Hat Network. 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.

Affected Products

• Red Hat Enterprise Linux Server 2 ia64
• Red Hat Enterprise Linux Workstation 2 ia64

Fixes

• BZ - 77647 - SMRSH security issues

CVEs

• CVE-2002-1165

References

(none)