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Our Polish friend and expert security researcher, Michal Zalewski (lcamtuf), known for his endless stream of vulnerabilities in all manners of software, has struck again.
This time with some pretty serious flaws in both Internet Exploder Explorer and Firefox. This time it’s 4, 2 in IE and 2 in Firefox.
The first which effects fully patched IE6 and IE7 is pretty serious and can result in cookie theft, cooking setting, page hijacking or memory corruption.
It’s based on a page update Race Condition (aka bait and switch vuln).
When Javascript code instructs MSIE6/7 to navigate away from a page that meets same-domain origin policy (and hence can be scriptually accessed and modified by the attacker) to an unrelated third-party site, there is a window of opportunity for concurrently executed Javascript to perform actions with the permissions for the old page, but actual content for the newly loaded page
The demo can be found here:
http://lcamtuf.coredump.cx/ierace/
The more serious of the two Firefox flaws is marked MAJOR and not CRITICAL and deals with the way the browser handles IFRAMEs (Cross-site IFRAME hijacking)
Javascript can be used to inject malicious code, including key-snooping event handlers, on pages that rely on IFRAMEs to display contents or store state data / communicate with the server.
A demo can be found here:
http://lcamtuf.coredump.cx/ifsnatch/
The full e-mail with details of his vulnerabilities can be found here:
[Full-disclosure] Assorted browser vulnerabilities
You can also read more at The Register or eWeek.
Daniel says
I really do think that as all the bugs are being shaken out of firefox and ie and out of OS’es that the exploit of the future will be in scripting languages.
backbone says
well you cannot consider script exploits so damage full, there are ment just for cookie stealing, session hijacking and so…. and os’es don’t phuck at this kind of job… ;)
therealdonquixote says
The FireFox vulns are pretty easy to avoid. For about:blank, limit what JS can do in your prefs under “advanced”. Don’t forget to have pop-ups blocked as well. Then use the extension TabmixPlus to force all javascript pop-ups to open in a new tab. As a bit of added security you can also have AdBlock Plus as an extension as well. Basically this kills the pop-under before it can load.
As for the iFrame vuln. This is a pretty easy one to deal with cause every webmaster on earth knows that the world hates iFrames, so they are kinda rare, which makes the following less annoying. Write a simple filter blocking iFrames with AdBlockPlus. You can always unblock them if you see that the site is secure. I keep an eye on what code is okey dokey and whats naughty with FireBug, good for spotting XSS before you walk into it. You could write a greasemonkey script to do the same, but that would be alot of work and a real pain in the ass. Plus I really don’t like greasemonkey, don’t know why.
If you don’t mind being nagged to death you can just keep the following extensions running all the time:
NoScript
Cookie Safe
Flashblock
-all nag all the time
on top of
AdBlockPlus – just nice to have really
TabMixPlus – purely to force those JS popups into tabs
FireBug – Also handy for ripping code or finding the actual locale of that video you want to rip off the web.
That set up will keep you safe as long as you only allow JS, Cookies and Flash from sites that you know you can trust.
I like my little tricks better though.
As for OS vulns, move to Linux. Its safer and just plain kewl.
thefakedonquixote says
AdBlockPlus does not serve any security purpose. It’s just an annoyance blocker, nice to have if you hate ads. Same for FlashBlock.
NoScript is the only must have, and it doesn’t “nag all the time”: actually, it’s quite discreet, you notice it only when some retard web designer forgets to code a no-JavaScript fallback.
In the meanwhile, it guards navigation against XSS in a much more convenient and effective way than “keep an eye on what code is okey dokey and whats naughty with FireBug, good for spotting XSS before you walk into it” 8)