Dear John Smith,
In general case we are discussing, DoS may be caused by e.g. some
combination of allowed tags/properties or by malformed image.
As it was pointed by author, this attack may be performed with
scripting disabled (with [iframe src=]). That's why e-mail vector may
be significant.
--Friday, May 28, 2010, 11:55:28 PM, you wrote to 3APA3A@xxxxxxxxxxxxxxxx:
JS> Point taken. But that'd be a non-issue on the browser's end as much as
JS> site's that is allowing the rogue scripts (or malformed ads, as per
your
JS> example).
JS> The fork of this mail thread clearly explains what I'm talking about.
The
JS> issue noted there is a simple DoS attack which every programming
language
JS> and platform is vulnerable too. Its called the "infinite loop". It is
not a
JS> 'security vulnerability' by itself and is completely agnostic of the
uri
JS> handler (try http or anything instead of nntp).
JS> Here's the simplified JS version of it (lets call it the Universal
DoS --
JS> yes, it'd work for every browser on the planet that can execute JS) -
JS> <script>
JS> while(1)alert('hello world');
JS> </script>
JS> Done!
JS> Workaround:
JS> None very intuitive. Maybe allow the user to terminate the script at
every
JS> iteration? specific time period? etc...
JS> --------------------------------------------------
JS> From: "Vladimir '3APA3A' Dubrovin" <3APA3A@xxxxxxxxxxxxxxxx>
JS> Sent: Friday, May 28, 2010 11:47 PM
JS> To: "John Smith" <at-x@xxxxxxxx>
JS> Cc: "MustLive" <mustlive@xxxxxxxxxxxxxxxxxx>; "Susan Bradley"
JS> <sbradcpa@xxxxxxxxxxx>; <bugtraq@xxxxxxxxxxxxxxxxx>
JS> Subject: Re[2]: DoS vulnerabilities in Firefox, Internet Explorer,
Chrome,
JS> Opera and other browsers
Dear John Smith,
Actually, browser DoS may be quite serious vulnerability, depending on
nature of DoS. Think about e.g. banner or content exchange network,
social networks, web boards, etc where browser vulnerability may be
used against site or page because it will harm any visitors of this
site or page.
In case of this very vulnerability, most serious impact may be from
e-mail vector.
--Friday, May 28, 2010, 7:07:50 PM, you wrote to
mustlive@xxxxxxxxxxxxxxxxxx:
JS> Just a few cents - DoS in webbrowsers doesn't fall under the
category
of
JS> "vulnerabilities" rather more of "annoyances". Although I don't deny
the
JS> fact that certain DoS attacks *may lead* or *may serve as hints* to
other
JS> more serious exploits, but that's a different topic and with ASLR in
the
JS> scene, a very grey area of discussion.
--
Skype: Vladimir.Dubrovin
~/ZARAZA http://securityvulns.com/
Стреляя во второй раз, он искалечил постороннего. Посторонним был я.
(Твен)
--
Skype: Vladimir.Dubrovin
~/ZARAZA http://securityvulns.com/
Машина оказалась способной к единственному действию,
а именно умножению 2x2, да и то при этом ошибаясь. (Лем)