RHSA-2004:174 - Security Advisory

Topic

An updated utempter package that fixes a potential symlink vulnerability is
now available.

Description

Utempter is a utility that allows terminal applications such as xterm and
screen to update utmp and wtmp without requiring root privileges.

Steve Grubb discovered a flaw in Utempter which allowed device names
containing directory traversal sequences such as '/../'. In combination
with an application that trusts the utmp or wtmp files, this could allow a
local attacker the ability to overwrite privileged files using a symlink.

Users should upgrade to this new version of utempter, which fixes this
vulnerability.

Solution

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.

If up2date fails to connect to Red Hat Network due to SSL
Certificate Errors, you need to install a version of the
up2date client with an updated certificate. The latest version of
up2date is available from the Red Hat FTP site and may also be
downloaded directly from the RHN website:

https://rhn.redhat.com/help/latest-up2date.pxt

Affected Products

• Red Hat Enterprise Linux Server 3 x86_64
• Red Hat Enterprise Linux Server 3 ia64
• Red Hat Enterprise Linux Server 3 i386
• Red Hat Enterprise Linux Server 2 ia64
• Red Hat Enterprise Linux Server 2 i386
• Red Hat Enterprise Linux Workstation 3 x86_64
• Red Hat Enterprise Linux Workstation 3 ia64
• Red Hat Enterprise Linux Workstation 3 i386
• Red Hat Enterprise Linux Workstation 2 ia64
• Red Hat Enterprise Linux Workstation 2 i386
• Red Hat Enterprise Linux Desktop 3 x86_64
• Red Hat Enterprise Linux Desktop 3 i386
• Red Hat Enterprise Linux for IBM z Systems 3 s390x
• Red Hat Enterprise Linux for IBM z Systems 3 s390
• Red Hat Enterprise Linux for Power, big endian 3 ppc

Fixes

• BZ - 121332 - CAN-2004-0233 utempter directory traversal symlink attack

CVEs

• CVE-2004-0233

References

(none)