These are not IE vulnerabilities. In all, you have described several ways to do some basic ressource exhaustion by using Internet Explorer as well as an abnomaly in the Apache server and a possible exploitable buffer overflow in Outlook Express. The latter is definitely interesting, provided it is exploitable at all, but the first items are not security vulnerabilities - details below. MAILTO: links simply open your default mail application, creates a new message and inserts the address in the To field. Whether or nor MS properly validates the format of the address is one thing but it is hardly a security vulnerability in IE. The only net effect of this is that you can insert arbitrary characters into the To field of an email message, which does not accomplish anything except ressource exhaustion when you open thousands of these. The lack of input validation in the SNEWS: URI simply means that you can add items to the list of servers in OE. Add a few thousands and we are possibly talking ressource exhaustion, but these can all be removed again without any other side effects. I was not able to disable backspace as you suggested by manually writing a link in the addressbar and clicking Enter, and even if I could I fail to see how this is a security vulnerability that could be used for "abusing simple people". Requesting a file called "styles" when a "style.css" file exists and having the contents from "styles.css" returned instead of a "404 Not Found" HTTP error is not a problem with IE, but a problem with Apache. Basic packet capturing and analysis will show you that IE is not requesting "something.css", but requesting "something" as you asked it to and, incorrectly, receiving "something.css" with incorrect headers from Apache. When Apache receives a request for "something" and "something.css" exists, it returns a "Content-Location: $yourRequest.css" header and includes the content of "something.css" in the response to the client, but incorrectly fails to include a "Content-Type: text/css" header. The lack of a proper MIME type for the content is the reason why you get an error box in IE, yet IE's internal content handler recognizes the CSS in the response from Apache and opens whichever application you have assigned to handle CSS files - in your case, Frontpage. IIS does the proper thing and returns a "404 Not Found" HTTP error. In your script examples you are calling a method called document.refresh; there is no refresh method on the document object, rather there is a reload method on the location object, location.reload(), as well as a Refresh argument to the execCommand method on the document object, document.execCommand("Refresh"). Also, the "long report error" with NNTP links is all it is - an error from Outlook Express that it does not recognize the format. This is not a vulnerability but simply a message box, which is even what you would like to have had instead of the lack of input validation on MAILTO and SNEWS. Personally, I could not reproduce your buffer overflow in OE which should occur when adding a news server with a long name. Automatically adding servers to the list of news servers is plain ressource exhaustion, but I could not find any overflows, exploitable or not, on my OE6 installations. I reported a similar exploitable buffer overflow in News server names in Outlook Express to Microsoft about a year ago, but it was only exploitable once you unsubscribed from the news server. It was since then silently patched (I didn't get a communication about that) but I guess they just moved the overflow around (provided others can reproduce your findings). Regards Thor Larholm Senior Security Researcher PivX Solutions 24 Corporate Plaza #180 Newport Beach, CA 92660 http://www.pivx.com thor@pivx.com 949-231-8496 PivX defines "Proactive Threat Mitigation". Get a FREE Beta Version of Qwik-Fix <http://www.qwik-fix.net> -----Original Message----- From: Rafel Ivgi, The-Insider [mailto:theinsider@012.net.il] Sent: Tuesday, January 20, 2004 1:08 PM To: bugtraq@securityfocus.com Subject: Internet Explorer - Multiple Vulnerabilities Snip http://www.securityfocus.com/archive/1/350423/2004-01-18/2004-01-24/0 Snip http://smallurl.com?i=5831