Statement

Red Hat Enterprise Linux 5 is now in Production 3 Phase of the support and maintenance life cycle. This has been rated as having Moderate security impact and is not currently planned to be addressed in future updates. For additional information, refer to the Red Hat Enterprise Linux Life Cycle: https://access.redhat.com/support/policy/updates/errata/.

This flaw only affects X clients that connect to malicious X servers. Generally speaking, these will be untrusted/unknown X servers only, as trusted remote X servers should be connected to via SSH (which provides end-point verification and authentication), or the local X server. Because this flaw requires that the X server be changed (recompiled to deviate from a standard X server) in order to impact the X client, it requires root privileges on the X server to effect the change. If this is a system where the X client and server are on the same (local) host, and an attacker is able to replace the X server binary, then they already have root privileges and no trust boundary is crossed. With remote X servers, using SSH with strict host-key checking will prevent the X client from connecting to the X server without intervention, as the user will be alerted to host-key changes.