Two bugs have been found in the X Display Manager Control Protocol (XDMCP) which could allow a denial of service attack (DoS) by crashing the gdm daemon. The Common Vulnerabilities and Exposures project (cve.mitre.org) has assigned the names CAN-2003-0548 and CAN-2003-0549 to these issues. This attack is only possible if XDMCP is enabled. XDMCP is not enabled by default in Red Hat Enterprise Linux distributions. In addition is documented best practise that XDMCP should only ever be run on trusted networks. Note that Red Hat Enterprise Linux 2.1 is not vulnerable to CAN-2003-0547, a vulnerability that allows a local user to read any text file, as it did not have the "examine session errors" feature (bug 102275)
An errata 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 the 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/RHSA-2003-259.html