Issued:

2013-09-05

Updated:

2013-09-05

RHSA-2013:1213 - Important: gdm security update

Synopsis

Important: gdm security update

Type/Severity

Security Advisory Important

Topic

Updated gdm and initscripts packages that fix one security issue are now available for Red Hat Enterprise Linux 5.

The Red Hat Security Response Team has rated this update as having important 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

The GNOME Display Manager (GDM) provides the graphical login screen, shown shortly after boot up, log out, and when user-switching.

A race condition was found in the way GDM handled the X server sockets directory located in the system temporary directory. An unprivileged user could use this flaw to perform a symbolic link attack, giving them write access to any file, allowing them to escalate their privileges to root. (CVE-2013-4169)

Note that this erratum includes an updated initscripts package. To fix CVE-2013-4169, the vulnerable code was removed from GDM and the initscripts package was modified to create the affected directory safely during the system boot process. Therefore, this update will appear on all systems, however systems without GDM installed are not affected by this flaw.

Red Hat would like to thank the researcher with the nickname vladz for reporting this issue.

All users should upgrade to these updated packages, which correct this issue. The system must be rebooted for this update to take effect.

Solution

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

This update is available via the Red Hat Network. Details on how to use the Red Hat Network to apply this update are available at https://access.redhat.com/site/articles/11258

Affected Products

Updated Packages

• initscripts-debuginfo-8.45.42-2.el5_9.1.x86_64.rpm
• gdm-2.16.0-59.el5_9.1.i386.rpm
• gdm-docs-2.16.0-59.el5_9.1.x86_64.rpm
• initscripts-debuginfo-8.45.42-2.el5_9.1.i386.rpm
• gdm-debuginfo-2.16.0-59.el5_9.1.ppc.rpm
• initscripts-debuginfo-8.45.42-2.el5_9.1.s390x.rpm
• initscripts-8.45.42-2.el5_9.1.ia64.rpm
• gdm-2.16.0-59.el5_9.1.ia64.rpm
• gdm-docs-2.16.0-59.el5_9.1.ia64.rpm
• initscripts-8.45.42-2.el5_9.1.s390x.rpm
• gdm-debuginfo-2.16.0-59.el5_9.1.s390x.rpm
• initscripts-debuginfo-8.45.42-2.el5_9.1.ia64.rpm
• initscripts-8.45.42-2.el5_9.1.x86_64.rpm
• gdm-docs-2.16.0-59.el5_9.1.i386.rpm
• gdm-debuginfo-2.16.0-59.el5_9.1.x86_64.rpm
• initscripts-8.45.42-2.el5_9.1.src.rpm
• initscripts-8.45.42-2.el5_9.1.ppc.rpm
• gdm-docs-2.16.0-59.el5_9.1.ppc.rpm
• gdm-2.16.0-59.el5_9.1.x86_64.rpm
• gdm-docs-2.16.0-59.el5_9.1.s390x.rpm
• gdm-debuginfo-2.16.0-59.el5_9.1.ia64.rpm
• initscripts-8.45.42-2.el5_9.1.i386.rpm
• gdm-debuginfo-2.16.0-59.el5_9.1.i386.rpm
• gdm-2.16.0-59.el5_9.1.src.rpm
• gdm-2.16.0-59.el5_9.1.ppc.rpm
• gdm-2.16.0-59.el5_9.1.s390x.rpm
• initscripts-debuginfo-8.45.42-2.el5_9.1.ppc.rpm

Fixes

• This content is not included.BZ - 988498

CVEs

• CVE-2013-4169

References

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

Additional information

• The Red Hat security contact is This content is not included.secalert@redhat.com. More contact details at https://access.redhat.com/security/team/contact/.
• Offline Security Data data is available for integration with other systems. See Offline Security Data API to get started.