By Thomas Kristensen, CTO
On Monday 30th October, Secunia published an advisory describing a vulnerability in IE7, which appears to be a legacy from IE6 - and which back in 2004 turned out to affect virtually every single browser on the market.
The vulnerability allows a malicious site to change the content of arbitrary pop up windows, see illustration of attack:
In 2004 the organisations behind Firefox, Netscape, Opera, Konqueror, OmniWeb, and Safari all confirmed the "Windows Injection" issue to be avulnerability and subsequently issued fixes for this issue.
Get the facts in Secunia Advisories regarding the other browsers:
- Firefox - fixed after 2 months
- Netscape - fixed after 6 months
- Opera - fixed after 2 months
- Konqueror - fixed within days
- Omniweb - fixed after 11 months
- Safari - fixed after 1 month
IE6 users had to change the "Navigate sub-frames across different domains" setting to protect themselves.
Today, in IE7 this setting has been disabled by default - that is a good thing - but it doesn't work - that is a bad thing!
That in itself qualifies for at least a "security bug".
Microsoft writes in their blog that they didn't consider this to be a vulnerability back in 2004 because it potentiallycould break functionality on websites!
Today, in 2006 they still say this isn't a vulnerability - despite the fact that they intended to protect users against this in IE7 by disabling the "Navigate sub-frames across different domains" "functionality" by default.
To defend Microsoft in all this,we agree that the newly added and always visible address bar does mitigate this - however, imagine this scenario:
* You enter your webbank
* You verifythe authenticity of the banks SSL certificate
* Then you click on a link, which pops up a login dialogue
Would you suspect that after you clickedthis link from your own trusted webbank that any malicious website which you have running in a different browser window could change the content of the pop-up?
Most likely not.
Even if the pop up now showed an IP address or my.webbank.com.cn instead of the usual my.webbank.com?
Would youreally read the full URL and spot the difference and think "ahh someone is "phishing" me now!"?
Well you may if you are really paranoid - most people aren't and they would easily be fooled.
If this "functionality" is required, then the setting to allow this dangerous interaction between different windows and pop ups can easily be enabled on a per site basis or for sites which are trusted.
We believe that Microsoft ought to take responsibility for the bugs, weaknesses, and vulnerabilities in their browser to ensure that it really protects against phishing and similar scam attacks - isn't this what Microsoft advertises that IE7 does better than it's predecessors?
Get the facts in Secunia Advisories: