Palladium and buffer over runs

[Frank Andrew Stevenson]

What is there to prevent that one single undisclosed buffer overrun bug in 
a component such as Internet Explorer won't shoot down the whole DRM 
scheme of Palladium ? Presumably IE will be able to run while the machine 
is in a trusted state, but if the IE can be subverted by injecting 
compromising code through a buffer overrun, the security of DRM material 
that is viewed in one window could be compromised through malicious code 
that has been introduced through another browser window.

The OS should change all memory pages to Read Only + Executable, after it 
has checked the signature of an application, and the CPU could trigger an 
exception if code is executed in a page that isn't tagged as Executable. 
However Windows and Intel CPUs don't work this way... Count the number of 
buffer over runs already found in IE, seems very likely that an attacker 
would be able to discover a new one without disclosing it...

  frank

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