RHSA-2009:1364 - Security Advisory

Topic

Updated gdm packages that fix a security issue and several bugs are now
available for Red Hat Enterprise Linux 5.

This update has been rated as having low security impact by the Red Hat
Security Response Team.

Description

The GNOME Display Manager (GDM) is a configurable re-implementation of XDM,
the X Display Manager. GDM allows you to log in to your system with the X
Window System running, and supports running several different X sessions on
your local machine at the same time.

A flaw was found in the way the gdm package was built. The gdm package was
missing TCP wrappers support, which could result in an administrator
believing they had access restrictions enabled when they did not.
(CVE-2009-2697)

This update also fixes the following bugs:

• the GDM Reference Manual is now included with the gdm packages. The

gdm-docs package installs this document in HTML format in
"/usr/share/doc/". (BZ#196054)

• GDM appeared in English on systems using Telugu (te_IN). With this

update, GDM has been localized in te_IN. (BZ#226931)

• the Ctrl+Alt+Backspace sequence resets the X server when in runlevel 5.

In previous releases, however, repeated use of this sequence prevented GDM
from starting the X server as part of the reset process. This was because
GDM sometimes did not notice the X server shutdown properly and would
subsequently fail to complete the reset process. This update contains an
added check to explicitly notify GDM whenever the X server is terminated,
ensuring that resets are executed reliably. (BZ#441971)

• the "gdm" user is now part of the "audio" group by default. This enables

audio support at the login screen. (BZ#458331)

• the gui/modules/dwellmouselistener.c source code contained incorrect

XInput code that prevented tablet devices from working properly. This
update removes the errant code, ensuring that tablet devices work as
expected. (BZ#473262)

• a bug in the XOpenDevice() function prevented the X server from starting

whenever a device defined in "/etc/X11/xorg.conf" was not actually plugged
in. This update wraps XOpenDevice() in the gdk_error_trap_pop() and
gdk_error_trap_push() functions, which resolves this bug. This ensures that
the X server can start properly even when devices defined in
"/etc/X11/xorg.conf" are not plugged in. (BZ#474588)

All users should upgrade to these updated packages, which resolve these
issues. GDM must be restarted for this update to take effect. Rebooting
achieves this, but changing the runlevel from 5 to 3 and back to 5 also
restarts GDM.

Solution

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

This update is available via 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 - 239818 - CVE-2009-2697 gdm not built with tcp_wrappers
• BZ - 441971 - [RHEL5] GDM sometimes doesn't come back after ctrl-alt-backspace
• BZ - 458331 - Add supplementary audio group to the gdm user
• BZ - 473262 - Mouse cursor not movable when using tablet instead of mouse
• BZ - 474588 - gdmgreeter crashes if input device (ex wacom) is defined but not plugged

CVEs

• CVE-2009-2697

References

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