GNOME Shell 3.14.x before 3.14.1, when the Screen Lock feature is used, does not limit the aggregate memory consumption of all active PrtSc requests, which allows physically proximate attackers to execute arbitrary commands on an unattended workstation by making many PrtSc requests and leveraging a temporary lock outage, and the resulting temporary shell availability, caused by the Linux kernel OOM killer.

gnome-settings-daemon was updated to fix a bug and a security issue :

Security issue fixed :

  - CVE-2014-7300: The lockscreen can be bypassed with the     Print Screen button.

Bug fixed :

  - Do not hide the cursor while there was no mutter running     (bsc#905158).

Note that Tenable Network Security has extracted the preceding description block directly from the SUSE security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

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.

  - 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.

  - 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.

  - 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.

  - 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.

  - 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.

  - 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.

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.

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.

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.

The remote Oracle Linux 7 host has packages installed that are affected by a vulnerability as referenced in the ELSA-2015-0535 advisory.

    clutter     [1.14.4-12]
    - Include upstream patch to prevent a crash when hitting hardware limits       Resolves: rhbz#1115162

    [1.14.4-11]
    - Fix a typo in the Requires

    [1.14.4-10]
    - Add patch for quadbuffer stereo suppport       Resolves: rhbz#1108891

    cogl     [1.14.1-6]
    - Add patches for quadbuffer stereo suppport       Resolves: rhbz#1108890

    [1.14.0-5.2]
    - Ensure the glBlitFramebuffer case is not hit for swrast, since that's       still broken.

    gnome-shell     [3.8.4-45]
    - Don't inform GDM about session changes that came from GDM       Resolves: #1163474

    [3.8.4-44]
    - If password authentication is disabled and smartcard authentication is       enabled and smartcard isn't plugged in at start up, prompt user for       smartcard       Resolves: #1159385

    [3.8.4-43]
    - Support long login banner messages more effectively       Resolves: #1110036

    [3.8.4-42]
    - Respect disk-writes lockdown setting       Resolves: rhbz#1154122

    [3.8.4-41]
    - Disallow consecutive screenshot requests to avoid an OOM situation       Resolves: rhbz#1154107

    [3.8.4-41]
    - Add option to limit app switcher to current workspace       Resolves: rhbz#1101568

    [3.8.4-40]
    - Try harder to use the default calendar application       Resolves: rhbz#1052201

    [3.8.4-40]
    - Update workspace switcher fix       Resolves: rhbz#1092102

    [3.8.4-39]
    - Validate screenshot parameters       Resolves: rhbz#1104694

    [3.8.4-38]
    - Fix shrinking workspace switcher       Resolves: rhbz#1092102

    [3.8.4-38]
    - Update fix for vertical monitor layouts to upstream fix       Resolves: rhbz#1075240

    [3.8.4-38]
    - Fix traceback introduced in 3.8.4-36 when unlocking via       user switcher       Related: #1101333

    [3.8.4-37]
    - Fix problems with LDAP and disable-user-list=TRUE       Resolves: rhbz#1137041

    [3.8.4-36]
    - Fix login screen focus issue following idle       Resolves: rhbz#1101333

    [3.8.4-35]
    - Disallow cancel from login screen before login attempt       has been initiated.
      Resolves: rhbz#1109530

    [3.8.4-34]
    - Disallow cancel from login screen after login is already       commencing.
      Resolves: rhbz#1079294

    [3.8.4-33]
    - Add a patch for quadbuffer stereo suppport       Resolves: rhbz#1108893

    mutter     [3.8.4.16]
    - Fix window placement regression       Resolves: rhbz#1153641

    [3.8.4-15]
    - Fix delayed mouse mode       Resolves: rhbz#1149585

    [3.8.4-14]
    - Preserve window placement on monitor changes       Resolves: rhbz#1126754

    [3.8.4-13]
    - Improve handling of vertical monitor layouts       Resolves: rhbz#1108322

    [3.8.4-13]
    - Add patches for quadbuffer stereo suppport       Fix a bad performance problem drawing window thumbnails       Resolves: rhbz#861507

Tenable has extracted the preceding description block directly from the Oracle Linux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

The remote Redhat Enterprise Linux 7 host has packages installed that are affected by a vulnerability as referenced in the RHSA-2015:0535 advisory.

    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.

Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

- Add gnome-settings-daemon-no-lockscreen-screenshot.patch :

  + media-keys: Disallow screenshots when locked     (boo#900031, bgo#737456, CVE-2014-7300).

Security fix for lock screen circumvention by consecutive screenshot requests triggering OOM situation

Note that Tenable Network Security has extracted the preceding description block directly from the Fedora security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

ID	Name	Product	Family	Severity
83700	SUSE SLED12 / SLES12 Security Update : gnome-settings-daemon (SUSE-SU-2015:0515-1)	Nessus	SuSE Local Security Checks	high
82249	Scientific Linux Security Update : GNOME Shell on SL7.x x86_64 (20150305)	Nessus	Scientific Linux Local Security Checks	high
81898	CentOS 7 : clutter / cogl / gnome-shell / mutter (CESA-2015:0535)	Nessus	CentOS Local Security Checks	high
81807	Oracle Linux 7 : GNOME / Shell (ELSA-2015-0535)	Nessus	Oracle Linux Local Security Checks	medium
81639	RHEL 7 : GNOME Shell (RHSA-2015:0535)	Nessus	Red Hat Local Security Checks	medium
78836	openSUSE Security Update : gnome-settings-daemon (openSUSE-SU-2014:1348-1)	Nessus	SuSE Local Security Checks	high
78569	Fedora 20 : gnome-shell-3.10.4-9.fc20 (2014-12690)	Nessus	Fedora Local Security Checks	high

Detections

Analytics

CVE-2014-7300

medium

Tenable Plugins

high

high

high

medium

medium

high

high