On: Firefox Under Fire: Anatomy of latest 0-day attack

[pcwalton]

> Instead of having to find 0-days for Adobe Reader on Windows, Evince/Okular on Linux, and others, they only had to find a flaw in PDF.js itself.

The overwhelming majority of Firefox users are on Windows, so statistically this doesn't result in the conclusion you think it does.

[marrs → pcwalton]

Yes it does. Statistically, all Linux users running Firefox have been adversely affected when they needn't have been.

[pcwalton → marrs]

Linux users of Firefox are a tiny minority of Firefox users. The overall diversity, when considering the ecosystem as a whole, doesn't change much with the addition of pdf.js.

Compared to the large improvement in security that the JS sandbox provides (and yes, sandboxes do improve security despite sometimes having holes) compared to (say) unsandboxed Evince, the security benefit from diversity is minimal.