286931 - CPU usage 100%, browser locks / exploit?

Status: RESOLVED WORKSFORME

(Firefox :: General, defect)

Description

[Daniel O'Connor]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7.6) Gecko/20050225 Firefox/1.0.1
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.7.6) Gecko/20050225 Firefox/1.0.1

Client recieves an email with "Hello! This postcard with the message is sent for
You... You can receive it during 7 days." as well as a link
(http://super1.mk-game.net/index.html)

On visiting the link (as I couldn't see why it would be harmful), the browser
locks and makes the entire computer unusable.

Reproducible: Always

Actual Results:  
Browser is slowed to a crawl.

Expected Results:  
Browser warns that a script is causing slowness in the browser and offers user
option to terminate.

Comment 1

[Daniel O'Connor]

Attachment: Testcase

Comment 2

[Daniel O'Connor]

This is probably a duplicate, I just had no idea how to describe it properly.

Comment 3

[Daniel Veditz [:dveditz]]

Neither the attachment nor the linked page cause CPU usage for me. Could it be
some feature I've turned off?  I don't get anything sensible out of unescaping
the shellcode, although that could simply be the exploit machine code after the
attack attempt breaks whatever it's attempting to break.

The description sounds like a Denial of Service attack, and although it might be
worse I'm clearing the security flag in the hopes that more eyes will help us
reproduce and track down the cause.

Comment 4

[Brendan Eich [:brendan]]

WORKSFORME, Firefox 1.0.1 on Linux.  The script and URLs, while bogus-looking,
should not cause harm.  Someone needs to reproduce this and say how others can
reproduce it, or better yet: diagnose it.

/be

Comment 5

[Martijn Wargers (dead)]

Firefox takes appr. 360MB of memory for me on the testcase, but that is also
what IE6 is doing.

Comment 6

[Brendan Eich [:brendan]]

Daniel, how much memory do you have?  How does IE behave with the same testcase?

/be

Comment 7

[Daniel O'Connor]

I'm reluctant to hammer my computer by checking if it affects me as badly in IE
to be honest.
It's an older computer, so the massive allocation of memory is probably the
issue - this machine sometimes has trouble finding its way to the desktop... 

IIRC it's 1.13Ghz / 256 MB RAM.

Comment 8

[Bob Clary [:bc] (inactive)]

looks like an IE exploit. Don't visit the url with MSIE unless you are really
sure of what you are doing.

http://www.k-otik.com/exploits/20041102.InternetExploiter.htm.php

Doesn't look like our bug unless you are looking for a script usage warning.

Comment 9

[Jesse Ruderman]

Worksforme as filed.  If you want, you can file a new, general bug asking for a
warning when a page tries to use too much memory, and attach a simpler testcase.
 If you do, please add a comment here with the number of the new bug.