Updated PAM packages fix bug in pam_xauth module

Updated PAM packages are now available for Red Hat Linux 7.1, 7.2, 7.3, and
8.0. These packages correct a bug in pam_xauth's handling of authorization
data for the root user.

[Updated 16 April 2003]
Added packages for Red Hat Linux on IBM iSeries and pSeries systems.

The pam_xauth module is used to forward xauth information from user to user
in applications such as 'su'.

Andreas Beck discovered that versions of pam_xauth supplied with Red Hat
Linux since version 7.1 would forward authorization information from the
root account to unprivileged users. This could be used by a local attacker
to gain access to an administrator's X session. In order to exploit this
vulnerability, the attacker would have to get the administrator, as root,
to use su to the account belonging to the attacker.

Users of pam_xauth are advised to upgrade to these errata packages, which
contain a patch that adds ACL (access control list) functionality to
pam_xauth and disallows root forwarding by default.

Versions of pam_xauth included in Red Hat Linux 7 and earlier disabled
passing of credentials from the root account to unprivileged users by
default and are not affected by this issue.

Thanks to Andreas Beck for reporting this issue.

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.

http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2002-1160
http://www.redhat.com/support/wpapers/redhat/newpam/tinkering.html

cookies, pam_xauth, root