Multiple Web Browsers - Denial of Service

________________________________________________________________________



                     One bug to rule them all

       IE5,IE6,IE7,IE8,Netscape,Firefox,Safari,Opera,Konqueror,

       Seamonkey,Wii,PS3,iPhone,iPod,Nokia,Siemens.... and more.

               Don't wet your pants - it's DoS only

________________________________________________________________________



Release mode: Tried hard to coordinate - gave up

Reference   : [GSEC-TZO-26-2009] - One bug to rule them all

WWW         : http://www.g-sec.lu/one-bug-to-rule-them-all.html

Vendors         : 

http://www.firefox.com   

http://www.apple.com

http://www.opera.com

http://www.sony.com

http://www.nintendo.com

http://www.nokia.com

http://www.siemens.com

others..

Status      : Varies

CVE         : CVE-2009-1692 (created by apple same root cause)

Credit      : Except Apple - nobody



Affected products : 

~~~~~~~~~~~~~~~~~

- Internet Explorer 5, 6, 7, 8 (all versions)

- Chrome (limited)

- Opera 

- Seamonkey

- Midbrowser

- Netscape 6 & 8 (9 years ago)

- Konqueror (all versions)

- Apple iPhone + iPod 

- Apple Safari

- Thunderbird

- Nokia Phones : Nokia N95 (Symbian OS v.9.2),Nokia N82, Nokia N810 Internet Tablet

- Aigo P8860 (Browser hangs and cannot be restarted)  

- Siemens phones

- Google T-Mobile G1 TC4-RC30

- Ubuntu (Operating system sometimes reboots, memory management failure)

- possibly more devices and products that support Javascript,

try it yourselves. POC here : http://www.crashthisthing.com/select.html



Patch availability :

~~~~~~~~~~~~~~~~~~

- Mozilla : Fixed in Firefox 3.0.5 and 2.0.0.19 

https://bugzilla.mozilla.org/show_bug.cgi?id=460713

- Apple iPhone&iPod : patched

- IE : No patch for IE5, IE6, IE7, IE8 until IE9

- Webkit : Patched in r41741 - https://bugs.webkit.org/show_bug.cgi?id=23319

- Chrome : Patched, unknown which version)

- Opera : Patched after version 9.64

- Thunderbird (unknown)

- Konqueror : unknown (did not respond)

- Nokia : unknown, opened a case but never came back

- Aigo P8860 : unknown

- Siemens : unknown

- Others ? Find out by visiting the POC at

http://crashthisthing.com/select.html





I. Background

~~~~~~~~~~~

Quoting Wikipedia "ECMAScript is a scripting language, standardized by Ecma 

International in the ECMA-262 specification and ISO/IEC 16262. The language 

is widely used on the web, especially in the form of its three best-known 

dialects, JavaScript, ActionScript, and JScript."





II. Description

~~~~~~~~~~~~~

Calling the select() method with a large integer, results in continuos

allocation of x+n bytes of memory  exhausting memory after a while. 

The impact varies from null pointer dereference (no more memory,hence 

crashing the browser) to the reboot of the complete Operation System 

(Konqueror&Ubuntu)



There had never been a limit specified as to how many html elements the select

call should handle, after the report of this Bug, vendors apparently agreed to a 

limit of 10.000 elements : "Talked to some Apple and Opera guys at the 

WHATWG social, and we decided this was a good number"



III. Impact

~~~~~~~~~

The Impact varies from Browser to Browser and from OS to OS. 



Here is a small excerpt:

- Konqueror (Ubuntu)- allocates 2GB of memory then either crashes 

the Browser or (most often) the OS reboots. Ubuntu's memory

management system appears to be configured as to NOT stop the process

that consumes too much memory, but a random process.

This sometimes leads to processes that are vital for the OS to

be killed, hence the reboot. I am not kidding. Thanks to

'FX' for Memory management hint.



- Chrome :  allocates 2GB of memory then crashes tab with a null pointer



- Firefox : allocates 2GB of memory then the Browser crashes



- IE5,6,7,8 : allocates 2GB of memory then the Browser crashes



- Opera : Allocated and commits as much memory as available, 

will not crash but other applications will become unstable 



- Nintento WII (Opera) : Console hangs, needs hard reset

Video: http://vimeo.com/2937101 (Thanks to David Raison)



- Sony PS3 - Console hangs, needs hard reset 

Video: http://vimeo.com/2937101 (Thanks to Chris Gates)



- iPhone - iPhone hangs and needs hard reset

Video: http://vimeo.com/2873339 (Thanks to g0tcha)



- Aigo P8860 (Browser hangs and cannot be restarted)  





IV. Proof of concept 

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

<script>

function poc(o) {

        e = document.createElement("select");

        e.length=2147483647;

}



function go() {

        poc(0);

}

</script>



URL: http://www.crashthisthing.com/select.html



Some have not understood what this code does, it does NOT loop as some vendors

claimed, it just calls select.lenght() ONCE with a huge integer. One might wonder

if over the 9 last years that this bug existed, nobody ever entered a large 

number in a select.lenght() call.



IV. Disclosure timeline

~~~~~~~~~~~~~~~~~~~~~~~

Nothing particular to note, except the usual discussion about availability being

a security issue.



V. Thanks

~~~~~~~~~~~~~~~~~~~~~~~

Chris Gates, David Raison, Fahem Adam, a team of engineers that recognise themselves

and oCert for not helping coordinate this bug.



# milw0rm.com [2009-07-15]