D-Bus is a system for sending messages between applications. It is used for the system-wide message bus service and as a per-user-login-session messaging facility. It was discovered that the D-Bus library honored environment settings even when running with elevated privileges. A local attacker could possibly use this flaw to escalate their privileges, by setting specific environment variables before running a setuid or setgid application linked against the D-Bus library . Note: With this update, libdbus ignores environment variables when used by setuid or setgid applications. The environment is not ignored when an application gains privileges via file system capabilities; however, no application shipped in Red Hat Enterprise Linux 6 gains privileges via file system capabilities. Red Hat would like to thank Sebastian Krahmer of the SUSE Security Team for reporting this issue. All users are advised to upgrade to these updated packages, which contain a backported patch to correct this issue. For the update to take effect, all running instances of dbus-daemon and all running applications using the libdbus library must be restarted, or the system rebooted.