Microsoft MSN Messenger Information Disclosure Vulnerability



Date Discovered

March 9, 2004


Microsoft MSN Messenger is prone to an information disclosure vulnerability. When a malformed file transfer request is initiated by a remote user, they may be able to view the contents of files on the remote system.

Technologies Affected

  • Microsoft MSN Messenger Service 6.0
  • Microsoft MSN Messenger Service 6.1


Do not accept communications that originate from unknown or untrusted sources.
If anonymous communications are blocked in MSN Messenger, the vulnerability could only be exploited by an attacker on the user's contact list. Blocking the reception of anonymous communications in MSN Messenger may limit the likelihood of exploitation.

When possible, limit the privileges granted to users to the least amount required.
A remote attacker could only view files that the vulnerable user has permissions to view. Limiting user access to sensitive files may help limit the consequences of successful exploitation.

Change the default location of executables, configuration files, directories, etc.
An attacker would have to know the name and location of files in order to view them through this vulnerability. Changing the default location of sensitive files may limit the information an attacker can gather through this vulnerability.

An updated version of MSN Messenger is available for download at:



Discovery is credited to qFox and Mephisto.

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