Hello Bugtraq! I want to warn you about security vulnerability in different browsers. ----------------------------- Advisory: DoS vulnerabilities in Firefox, Internet Explorer, Chrome, Opera and other browsers ----------------------------- URL: http://websecurity.com.ua/4206/ ----------------------------- Affected products: Mozilla Firefox, Internet Explorer 6, Internet Explorer 8, Google Chrome, Opera and other browsers. ----------------------------- Timeline: 16.05.2010 - found vulnerability. 17.05.2010 - disclosed at my site. 18.05.2010 - informed developers: Mozilla, Microsoft, Google and Opera. ----------------------------- Details: At 30.02.2010 Mozilla fixed vulnerability (small one, which poses no security risk, as they said), found by Henry Sudhof - Mozilla Foundation Security Advisory 2010-23 (http://www.mozilla.org/security/announce/2010/mfsa2010-23.html) (Image src redirect to mailto: URL opens email editor). Which allow to open email client at user's computer via redirector, which redirecting to mailto: URL. But this vulnerability was fixed only in Firefox 3.5.9, Firefox 3.6.2 and SeaMonkey 2.0.4, but not in Firefox 3.0.x. After I recently read this advisory, I decided to check different browsers. And as I checked at 16.05.2010, to this vulnerability are vulnerable web browsers Firefox 3.0.19 and Opera 9.52. And I created exploit for conducting of DoS attack on Firefox. Also I found possibility to open email client via iframe with mailto: URL. Which works in browsers Firefox 3.0.19, IE6, IE8 and Chrome. And I created exploit for conducting of attack on all browsers, which I called DoS via email. This attack can be conducted as with using JS, as without it (via creating of page with large quantity of iframes). If attack via images at a page (which open email client) is only discomfort, then attack via images or iframes with using my exploits is Denial of Service vulnerability. It belongs to type (http://websecurity.com.ua/2550/) blocking DoS and resources consumption DoS. These exploits are very dangerous - at their starting, if to not stop attack in time, they can lead to full consumption of computer's resources (potentially even to freezing of the system). DoS: http://websecurity.com.ua/uploads/2010/Firefox%20DoS%20Exploit.html This exploit works in Mozilla Firefox (Firefox <= 3.0.19, Firefox < 3.5.9, Firefox < 3.6.2) and SeaMonkey < 2.0.4. http://websecurity.com.ua/uploads/2010/Firefox,%20IE,%20Chrome%20&%20Ope ra%20DoS%20Exploit.html This exploit works in Mozilla Firefox (besides 3.0.x and previous versions, it must work in 3.5.x and 3.6.x), Internet Explorer 6 (6.0.2900.2180), Internet Explorer 8 (8.0.7600.16385), Google Chrome 1.0.154.48 and Opera 9.52. At that in Opera the exploit don't open email client, so DoS attack is going without blocking, only resources consumption (more slowly then in other browsers). And also this exploit must work in SeaMonkey, Internet Explorer 7 and other browsers. Best wishes & regards, MustLive Administrator of Websecurity web site http://websecurity.com.ua