Microsoft Edge CDOMTextNode::get_data type confusion

[Berend-Jan Wever <berendjanwever@xxxxxxxxx>]

Hey,

Last Tuesday, Microsoft fixed a security issue in Microsoft Edge that I
was aware of, but had not had time to report. (i.e. I was waiting for
vulnerability contributor programs to look over my analysis and make me
an offer for the information). Since this issue has been fixed, I have
published my analysis on my blog
<http://blog.skylined.nl/20160310001.html> at
http://blog.skylined.nl/20160310001.html.

In short: Specially crafted Javascript inside an HTML page can trigger a
type confusion bug in Microsoft Edge that allows accessing a C++ object
as if it was a BSTR string. This can result in information disclosure,
such as allowing an attacker to determine the value of pointers to other
objects and/or functions. This information can be used to bypass ASLR
mitigations. It may also be possible to modify arbitrary memory and
achieve remote code execution, but this was not
investigated.

Cheers,

SkyLined