To whom it may concern.
The so-called Cross-Origin Resource Sharing (CORS) web functionality
can constitute a very serious vulnerability in terms of both security
and privacy: the risks might not outweigh the benefits.
Most recent web browsers implement such functionality but unfortunately
do not offer a way of disabling it in order to gain maximum security
and privacy benfits while browsing the web.
SELinux policy, to the best of my knowledge, cannot prevent such
vulnerability either.
Therefore, the problem has to be tackled at the browser code level.
For those using the popular webkit library, a countermeasure for the
above mentioned vulnerability now exists in the form of a patch that I
have created:
https://bugs.webkit.org/show_bug.cgi?id=179886
Feel free to use it and/or redistribute it as long as you agree to the
webkit license and keep the copyright notice intact.
Regards,
Guido