A buffer overflow vulnerability exists in the Microsoft SQLXML Internet Services Application Programming Interface (ISAPI) extension for Internet Information Server (IIS). This vulnerability could allow a remote attacker to cause a denial of service or execute arbitrary code with LocalSystem privileges.
Microsoft SQL Server 2000 includes a feature called SQLXML that allows the server to handle SQL queries and responses via XML. IIS enables XML over HTTP using SQLXML HTTP components, one of which is an ISAPI extension. A client SQLXML HTTP request takes the form of a URI that contains a number of arguments including the name of the IIS server, the virtual directory (virtual root), and optional parameters. One of the optional parameters, contenttype, sets the Content-Type header for the HTTP response to the client. The entire URI, including the contenttype parameter, is controlled by the client.
The SQLXML ISAPI extension does not adequately validate the length of the contenttype parameter. As a result, an attacker could construct a URI with a specially crafted value for contenttype that triggers a buffer overflow on a vulnerable IIS server.
A remote attacker could execute arbitrary code or cause a denial of service. The SQLXML ISAPI extension runs as LocalSystem.
The CERT/CC thanks both Matt Moore of Westpoint and Microsoft for information used in this document.
This document was written by Art Manion.
|Date First Published:||2002-06-25|
|Date Last Updated:||2002-08-08 19:28 UTC|