Vulnerability Note VU#179804

Common Desktop Environment (CDE) dtlogin XDMCP parser improperly deallocates memory

Original Release date: 24 Mar 2004 | Last revised: 23 Jun 2004


A "double-free" vulnerability in the CDE dtlogin program could allow a remote attacker to execute arbitrary code or cause a denial of service on a vulnerable system.


The Common Desktop Environment (CDE) is an integrated graphical user interface that runs on UNIX and Linux operating systems. The dtlogin program contains a "double-free" vulnerability that can be triggered by a specially crafted X Display Manager Control Protocol (XDMCP) packet.


Depending on configuration, operating system, and platform architecture, an unauthenticated, remote attacker could execute arbitrary code, read sensitive information, or cause a denial of service.


The CERT/CC is currently unaware of a practical solution to this problem. Updated vendor information will be made available in the Systems Affected section below.

Block or Restrict XDMCP Traffic

Block XDMCP traffic (177/udp) from untrusted networks such as the Internet. Keep in mind that blocking ports at a network perimeter does not protect the vulnerable service from the internal network. In most cases, it is trivial for an attacker to spoof the source of a UDP packet, so restricting xdmcp access to specific IP addresses may be ineffective. Consider network configuration and service requirements before deciding what changes are appropriate.

Disable xdmcp in dtlogin

Depending on service requirements, disable XDMCP support in dtlogin.

On a SunOS 5.8 system:



#  To disable listening for XDMCP requests from X-terminals.
Dtlogin.requestPort:       0

Systems Affected (Learn More)

VendorStatusDate NotifiedDate Updated
Hewlett-Packard CompanyAffected23 Mar 200418 Jun 2004
IBMAffected23 Mar 200418 Jun 2004
SCOAffected23 Mar 200404 Apr 2004
SGIAffected23 Mar 200410 May 2005
Sun Microsystems Inc.Affected23 Mar 200423 Jun 2004
Cray Inc.Unknown-24 Mar 2004
EMC CorporationUnknown-24 Mar 2004
The Open GroupUnknown-24 Mar 2004
Xi GraphicsUnknown-24 Mar 2004
If you are a vendor and your product is affected, let us know.

CVSS Metrics (Learn More)

Group Score Vector
Base N/A N/A
Temporal N/A N/A
Environmental N/A N/A



This vulnerability was publicly reported by Dave Aitel of Immunity, Inc.

This document was written by Art Manion.

Other Information

  • CVE IDs: CAN-2004-0368
  • Date Public: 23 Mar 2004
  • Date First Published: 24 Mar 2004
  • Date Last Updated: 23 Jun 2004
  • Severity Metric: 25.82
  • Document Revision: 23


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