CentOS has released updated packages to address the D-Bus library dbus-glib message filter privilege escalation vulnerability.
Description
D-Bus Library contains a vulnerability that could allow a local attacker to gain elevated privileges on a targeted system.
The vulnerability is due to the message filtering mechanism used by the affected software. A local, unprivileged attacker could exploit this vulnerability by passing a crafted NameOwnerChanged variable signal to the system. Successful exploitation could allow an attacker to gain elevated privileges on the system.
Freedesktop.org has confirmed this vulnerability and software updates are available.
Warning Indicators
D-Bus dbus-glib versions prior to 0.100.1 are vulnerable.
IntelliShield Analysis
To exploit this vulnerability, the attacker must have local access to a targeted system. This access restriction limits the possibility of a successful exploit.
The vulnerability is also exploitable on the system using dbus-glib such as pam_fprintd. The vendor has recommended GLib application and library authors to switch to GDBus, which has been part of GLib since 2.26.
Vendor Announcements
Freedesktop.org has released a changelog at the following link: CVE-2013-0292
Red Hat has released an official CVE statement and a security advisory for bug 911658 at the following links: CVE-2013-0292 and RHSA-2013:0568
Impact
A local, unprivileged attacker could exploit this vulnerability to gain elevated privileges on a targeted system. These privileges could be used to perform further attacks on the system.
Technical Information
The vulnerability is in the dbus-gproxy.c source code of the affected software due to incorrect handling of a system signal. While filtering the message sender when a NameOwnerChanged signal is received, the software could fail to verify the message source subject. Due to this error, an unprivileged user on the DBus interface could generate the NameOwnerChanged signal with malformed message owner information. This may cause the affected software to process messages from unprivileged sources with elevated privileges.
A local, unprivileged attacker could exploit the vulnerability by generating crafted NameOwnerChanged signals on the targeted system and transmitting a DBus ownership message to the system. This could allow the attacker to gain elevated privileges to the DBus resource.
Safeguards
Administrators are advised to apply the appropriate updates.
Administrators are advised to allow only trusted users to access local systems.
Administrators are advised to monitor affected systems.
Patches/Software
Freedesktop.org has released software updates at the following link: dbus-glib 0.100.1
CentOS packages can be updated using the up2date or yum command.
Red Hat has released updated software for registered subscribers at the following link: Red Hat Network. Red Hat packages can be updated on Red Hat Enterprise Linux versions 5 and later using the yum tool.
Alert History
Version 2, March 1, 2013, 8:20 AM: CentOS has released updated packages to address the D-Bus library dbus-glib message filter privilege escalation vulnerability.
Version 1, February 27, 2013, 6:07 AM: D-Bus Library contains a vulnerability that could allow a local, unprivileged attacker to gain elevated privileges on a targeted system. Updates are available.
The security vulnerability applies to the following combinations of products.
Primary Products:
freedesktop.org
D-Bus
0.23 Base | 0.31 Base | 0.32 Base | 0.33 Base | 0.34 Base | 0.35 Base | 0.36 Base | 0.50 Base | 0.61 Base | 0.62 Base | 0.90 Base | 0.91 Base | 0.92 Base
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