A software patch issued by Microsoft Monday restores its Internet Explorer (IE) Web browser's ability to handle certain types of Web URLs (uniform resource locators) that were banned by an emergency browser security patch in early February.
The patch restores IE's ability to handle a type of HTTP (Hypertext Transfer Protocol) URL containing user authentication information such as user name and password information. The patch was issued after Web developers reported problems due to a critical security update for IE, MS04-004, which disabled such URLs.
That patch was intended to plug a security hole that allowed malicious hackers and online scam artists to mask the URL of a Web page by manipulating the way IE handles URLs that contain user credentials such as a user name and password.
The new IE software patch fixes the browser's ability to handle commands embedded in Web pages using an IE component called XMLHTTP (Extensible Markup Language Hypertext Transfer Protocol), which allows Web clients to access XML documents on remote Web servers using HTTP.
Some Web site developers use XMLHTTP to access resources on remote Web domains requiring user authentication. Requests that used XMLHTTP calls to pass URLs and authentication information stopped working after Microsoft released the MS04-004 patch for IE, according to comments posted on an online discussion list hosted by Microsoft and designed to provide information about XML and the company's products.
The software update affects Microsoft XML Service Pack 2, Service Pack 3 and Service Pack 4 and is available through a link in Microsoft Knowledge Base Article 832414. (See: http://support.microsoft.com/default.aspx?scid=kb;en-us;832414.)
Web sites that use XMLHTTP calls along with URLs containing user authentication information in the format "username:email@example.com" will still be blocked by IE, even after the latest patch has been applied, Microsoft said. However, requests that use the XMLHTTP object and proper syntax for breaking out user name and password information from the HTTP URL will now work with IE browsers that have applied the patch, Microsoft said.