This bug has been copied from bug #607368 and has been proposed to be backported to 4.8 z-stream (EUS).
An advisory has been issued which should help the problem described in this bug report. This report is therefore being closed with a resolution of ERRATA. For more information on therefore solution and/or where to find the updated files, please follow the link below. You may reopen this bug report if the solution does not work for you. http://rhn.redhat.com/errata/RHBA-2010-0570.html
Technical note added. If any revisions are required, please edit the "Technical Notes" field accordingly. All revisions will be proofread by the Engineering Content Services team. New Contents: When using the tcsh shell, a null pointer dereference in proc cwd could occur on some terms and cause a crash of the shell. This update provides a fix to the relevant part of the source code.