These days the news is current: 46 of the 50.000 most popular websites are sniffing your browsers history¬†[1]. The approach making this security vulnerability is simple and possible – a real lateral approach. The browser has a list of URL’s to check to be previously visited.

The links are written on the website on the fly and then the link’s style is read again. Links can have therefore four styles: active, hover, unvisited and visited. The first two are not interesting here. The last two can be used to distinguish between visited and not visited sites.

The downside of this approach is that a predefined list only can be evaluated. Even though it’s only possible in time and if JavaScript is activated – for that site. But this is the first approach letting websites access information from other ones – even though only a few.

This¬†vulnerates the so called Same Origin Policy on the web. Websites can leave information on the client but only can see and read their own ones. So it is not here! Even the “private browsing” features in many web display engines are knocked out here. Stay tuned for updates: these problems ought to be fixed soon.

[1] http://www.golem.de/1012/79943.html