[ConservativeMind]

I've read the paper about the BSD exploit and it is a real problem. It described multiple ways to infer what was being done on the rest of the processor with moderately high to perfect precision. The next unpatched exploit could allow this to happen, communicating the data flow over a reasonably fast connection (the process requires a lot of overhead to do the inferring, so the traffic can't be the full bandwidth).

Intel is already looking at the fixes necessary for a processor microcode patch, if possible (via BIOS upgrade).

The original paper was barely a dozen pages or so in PDF format.

[HiTech RedNeck]

You can overwrite an Intel chip's microcode from BIOS? I guess that means you could turn a Pentium into a chunk of useless metal too, with a virus (by writing a junk microcode into it). Or, simply turn the Pentium into a trojan.