Comment by NavinF
6 months ago
IMO that shouldn't be part of the threat model. I could run an ad right now that consumes CPU in timed intervals and estimates CPU usage using a microbenchmark to communicate with js on other pages. This sort of fingerprinting and bits/minute side-channels are impractical to block. You'd have to give each origin its own CPU cores, cache partitions, etc
Sigh. You don't prune threats you can't control from a threat model, you document them so that the consumers and maintainers of the target of assessment can intelligently reason about the threats as the product evolves.