Microsoft is planning an update to the cross-site scripting filter in Internet Explorer 8 to address an attack scenario revealed at the Black Hat Europe security conference.
At the conference, security researchers David Lindsay and Eduardo Vela Nava revealed details of how the filter detects attacks, as well as its strengths and weaknesses. The weakness included ways the filters could be abused and bypassed to enable cross-site scripting (XSS) on sites that would otherwise be safe, such as Twitter and Google.
“To begin with, the neutering mechanism (of Microsoft’s XSS filter) can be abused by an attacker to block benign content on a page,” the duo wrote in a research paper. “For example, embedded JavaScript can be blocked from executing by “faking” a XSS attack. This is possible since the string