Saturday, January 30, 2010

Little bug in Safari and Google Chrome

I guess a bug in Safari it's not a surprise at all but Google Chrome seems to be a more secure product. Anyways this little bug is not big deal but maybe combined with other bug it could be more dangerous.

The code above should display the same href value as in the LINK tag but it displays the final URL if there is a redirection, here in my country when you browse to you get redirected to so the above code displays this last URL.

Why this is an issue?
-There are some websites that put user session ids on the URL querystrings the same for tokens used for CSRF protection, if an attacker can get a user browsing his website then he can use the above code to reference a URL of a website the user is logged on that will be redirected to another URL that could have a session id or token in the querystring and then use this information for more dangerous attacks. Some websites could also have in the querystring some other useful information that could be used for further attacks. Websites putting session ids, tokens, etc. in querystings are already not secure but this issue helps in exploiting them.

-An attacker can also use this issue to determine if a user is logged in or not by comparing if the original URL is the same as the final one when trying to access a feature thar requires to be logged in.

-Maybe there are other possible ways of abusing this issue that I'm not aware right now.

Microsoft Internet Explorer and Mozilla Firefox are not vulnerable to this.


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