January 28th, 2004, 22:31 PM
New Explorer hole could be devastating
Browser users could be fooled into downloading executable files
By Kieren McCarthy, Techworld.com January 28, 2004
A security hole in Microsoft Corp.’s Internet Explorer could prove devastating. Following the exposure of a vulnerability in Windows XP earlier this week, “http-equiv” of Malware has revealed that Explorer 6 users (and possibly users of earlier versions) could be fooled into downloading what look like safe files but are in fact whatever the author wishes them to be -- including executables.
A demonstration of the hole is currently on security company Secunia’s website and demonstrates that if you click on a link, and select “Open” it purports to be downloading a pdf file whereas in fact it is an HTML executable file.
It is therefore only a matter of imagination in getting people to freely download what could be an extremely dangerous worm -- like, for instance, the Doom worm currently reeking havoc across the globe.
However what is more worrying is that this hole could easily be combined with another Explorer spoofing problem discovered in December.
The previous spoofing problem allowed Explorer users to think they were visiting one site when in fact they were visiting somewhere entirely different. The implications are not only troublesome, but Microsoft’s failure to include a fix for the problem in its January patches has led many to believe it cannot be prevented.
time to move to netscape
January 29th, 2004, 00:12 AM
Old and Cranky
Lemme see...spoofing IE addresses which ws discovered, oh, how long ago?
January 29th, 2004, 15:29 PM
Could they not just have something to verify the file's header information against the file type, check if it contains any other mischievous headers? Although isn't this suppose to be what Anti Virus should do.
January 29th, 2004, 15:51 PM
Microsoft to Change IE Behavior to Block Spoofing Attacks
Microsoft Corp. has announced in a support document that it will be releasing a software update to Internet Explorer and Windows Explorer to disable the use of certain syntax in HTTP URLs. The syntax, designed to allow a username and password to be passed to a password-protected page, has a history of abuse. The company did not give a timeline for the release of the patch.
The syntax takes the form http[s]://username: password@server/file.html, such as http://joe:firstname.lastname@example.org/, where "joe" is the username and "blow" is the password. But a site that does not look for the username and password will ignore the values passed, and only the string after the "@" symbol is used for the domain name. Other browsers support this syntax to varying degrees.
Because the values before "@" are ignored, attackers have often attempted to use them to confuse users into believing that they are going to a different site than they are actually visiting. For example, the URL http://www.microsoft.com%2F@10.11.12.13/ might appear to be going to www.microsoft.com, but it is actually going to the IP address 10.11.12.13.
The problem was compounded by the recent discovery of a display bug in Internet Explorer that stops the browser from displaying parts of the URL. This allows an attacker utilizing both techniques to display only the legitimate looking portion of the URL to the user.
Microsoft took some time deciding how to address the problem, but on Tuesday released the support document. After installing the patch, Internet Explorer will react to the syntax with a Web page containing the following error message: "Invalid syntax error." A registry entry will be available for users to re-enable the feature, or to enable it in third-party software that uses the IE Web browser control.
View: Microsoft Knowledge Base Article - 834489