Software Engineering Institute

Microsoft IIS servers support the HTTP TRACK method. The HTTP TRACK method asks a web server to echo the contents of the request back to the client for debugging purposes. The TRACK request is not RFC compliant and not well documented.

The complete request, including HTTP headers, is returned in the entity-body of a TRACK response. This leads to a Cross-site Scripting attack. Using features that provide client-side HTTP protocol support, such as XMLHTTP ActiveX or XMLDOM scripting objects, a web site can cause browsers to issue TRACK requests. The site can read the TRACK response, including sensitive header information such as cookies or authentication data.

Because the TRACK method is similar to the TRACE method, when combined with cross-domain browser vulnerabilities (VU#244729, VU#711843, VU#728563), HTTP TRACK and client-side HTTP support can be leveraged by attackers to read sensitive header information from third-party domains. This technique has been termed "Cross-Site Tracing," or XST, in a report published by WhiteHat Security. As noted in the report, the technique can be used to bypass the HttpOnly cookie attribute introduced in Microsoft Internet Explorer 6.0 SP1. HttpOnly blocks script access to the cookie property (document.cookie), but does not prevent a scripting object from reading the cookie out of an HTTP TRACK response.

IIS 6 is reported to be not vulnerable.

Attackers may abuse HTTP TRACK functionality to gain access to information in HTTP headers such as cookies and authentication data. In the presence of other cross-domain vulnerabilities in web browsers, sensitive header information could be read from any domains that support the HTTP TRACK method.

Microsoft IIS 6 is reported to be not vulnerable. The TRACK method can be added to Microsoft's URLScan DenyVerbs section. It should not be in the AllowVerbs section in the urlscan.ini file.