RHSA-2015:0535 - Security Advisory

Topic

Updated gnome-shell, mutter, clutter, and cogl packages that fix one security
issue, several bugs, and add one enhancement are now available for Red Hat
Enterprise Linux 7.

Red Hat Product Security has rated this update as having Low security impact. A
Common Vulnerability Scoring System (CVSS) base score, which gives a detailed
severity rating, is available from the CVE link in the References section.

Description

GNOME Shell and the packages it depends upon provide the core user interface of
the Red Hat Enterprise Linux desktop, including functions such as navigating
between windows and launching applications.

It was found that the GNOME shell did not disable the Print Screen key when the
screen was locked. This could allow an attacker with physical access to a system
with a locked screen to crash the screen-locking application by creating a large
amount of screenshots. (CVE-2014-7300)

This update also fixes the following bugs:

• The Timed Login feature, which automatically logs in a specified user after a

specified period of time, stopped working after the first user of the GUI logged
out. This has been fixed, and the specified user is always logged in if no one
else logs in. (BZ#1043571)

• If two monitors were arranged vertically with the secondary monitor above the

primary monitor, it was impossible to move windows onto the secondary monitor.
With this update, windows can be moved through the upper edge of the first
monitor to the secondary monitor. (BZ#1075240)

• If the Gnome Display Manager (GDM) user list was disabled and a user entered

the user name, the password prompt did not appear. Instead, the user had to
enter the user name one more time. The GDM code that contained this error has
been fixed, and users can enter their user names and passwords as expected.
(BZ#1109530)

• Prior to this update, only a small area was available on the GDM login screen

for a custom text banner. As a consequence, when a long banner was used, it did
not fit into the area, and the person reading the banner had to use scrollbars
to view the whole text. With this update, more space is used for the banner if
necessary, which allows the user to read the message conveniently. (BZ#1110036)

• When the Cancel button was pressed while an LDAP user name and password was

being validated, the GDM code did not handle the situation correctly. As a
consequence, GDM became unresponsive, and it was impossible to return to the
login screen. The affected code has been fixed, and LDAP user validation can be
canceled, allowing another user to log in instead. (BZ#1137041)

• If the window focus mode in GNOME was set to "mouse" or "sloppy", navigating

through areas of a pop-up menu displayed outside its parent window caused the
window to lose its focus. Consequently, the menu was not usable. This has been
fixed, and the window focus is kept in under this scenario. (BZ#1149585)

• If user authentication is configured to require a smart card to log in, user

names are obtained from the smart card. The authentication is then performed by
entering the smart card PIN. Prior to this update, the login screen allowed a
user name to be entered if no smart card was inserted, but due to a bug in the
underlying code, the screen became unresponsive. If, on the other hand, a smart
card was used for authentication, the user was logged in as soon as the
authentication was complete. As a consequence, it was impossible to select a
session other than GNOME Classic. Both of these problems have been fixed. Now, a
smart card is required when this type of authentication is enabled, and any
other installed session can be selected by the user. (BZ#1159385, BZ#1163474)

In addition, this update adds the following enhancement:

• Support for quad-buffer OpenGL stereo visuals has been added. As a result,

OpenGL applications that use quad-buffer stereo can be run and properly
displayed within the GNOME desktop when used with a video driver and hardware
with the necessary capabilities. (BZ#861507, BZ#1108890, BZ#1108891, BZ#1108893)

All GNOME Shell users are advised to upgrade to these updated packages, which
contain backported patches to correct these issues and add this enhancement.

Solution

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

For details on how to apply this update, refer to:

https://access.redhat.com/articles/11258

Affected Products

• Red Hat Enterprise Linux Server 7 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.7 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.6 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.5 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.4 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.3 x86_64
• Red Hat Enterprise Linux Server - AUS 7.7 x86_64
• Red Hat Enterprise Linux Server - AUS 7.4 x86_64
• Red Hat Enterprise Linux Workstation 7 x86_64
• Red Hat Enterprise Linux Desktop 7 x86_64
• Red Hat Enterprise Linux for IBM z Systems 7 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.7 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.6 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.5 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.4 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.3 s390x
• Red Hat Enterprise Linux for Power, big endian 7 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.7 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.6 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.5 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.4 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.3 ppc64
• Red Hat Enterprise Linux for Scientific Computing 7 x86_64
• Red Hat Enterprise Linux Server from RHUI 7 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.7 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.6 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.5 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.4 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.3 x86_64
• Red Hat Enterprise Linux Server - AUS 7.6 x86_64
• Red Hat Enterprise Linux Server - AUS 7.3 x86_64
• Red Hat Enterprise Linux Server - TUS 7.7 x86_64
• Red Hat Enterprise Linux Server - TUS 7.6 x86_64
• Red Hat Enterprise Linux Server - TUS 7.3 x86_64
• Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 7.7 x86_64
• Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 7.6 x86_64
• Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 7.4 x86_64
• Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 7.3 x86_64

Fixes

• BZ - 1043571 - Timed Login Failure
• BZ - 1052201 - Details -- Default Applications -- calendar
• BZ - 1092102 - workspaces thumbnails in overview too narrow with large number of workspaces
• BZ - 1108322 - Qt menu placement problem with gnome-shell and vertical monitors
• BZ - 1126754 - Workspace window placement is not persistent if monitors are switched
• BZ - 1137041 - GDM hangs when cancelling ldap user login
• BZ - 1147917 - CVE-2014-7300 gnome-shell: lockscreen bypass with printscreen key
• BZ - 1149585 - sloppy/mouse focus mode break with long pull-down menus
• BZ - 1153641 - [multi-head] Window is moved on its own to other screen
• BZ - 1154107 - CVE-2014-7300 gnome-shell: lockscreen bypass with printscreen key [rhel-7.1]
• BZ - 1154122 - Respect disable-save-to-disk lockdown setting
• BZ - 1159385 - GDM does not prompt for smartcard
• BZ - 1163474 - pam_pkcs11 with card_only breaks session selection

CVEs

• CVE-2014-7300

References

• https://access.redhat.com/security/updates/classification/#low