1. Telemetry as implemented is usually sloppy. Even though intuitively one could think that telemetry means “data gets collected locally and fired off to a remote server”, we have seen time and time again that they also build a return path to make the telemetry gathering more powerful. That return path can be a vector.
2. Web browsers have a _huge_ surface and they connect to remote servers constantly. The industry does very well at being proactive and at addressing CVEs but the whole premise makes that very difficult and so we cannot absolutely claim that browsers don’t have RCE(s).
[–] embedding-shape 1 day ago
[–] Someone 1 day ago
API protocol says “return value is either “OK” or “ERR””, attacker sends “Floccinaucinihilipilification”, overflowing the 3-byte response buffer allocated on the stack.
[–] embedding-shape 1 day ago
I'm claiming if "everything else" does indeed lead to a RCE, you're again doing something very wrong here. It's not rocket science exactly.
[–] Someone 1 day ago
- https://en.wikipedia.org/wiki/Stack_buffer_overflow#stack_sm...
- https://en.wikipedia.org/wiki/Return-oriented_programming
I think that’s how lots of RCE bugs start, so it may not be rocket science, but lots of software falls for it.
What return path could possibly lead to a RCE? That's crazy, no telemetry requires "backend could return any command that gets run on the client", you're doing telemetry in a very non-standard way if this is even possible.
At worst, the telemetry backend might first send the client a config, but none of that would contain executable commands because again, that'd be crazy.
> we cannot absolutely claim that browsers don’t have RCE(s).
Of course, you can never prove the absence of bugs (and/or security issues), but given that browsers aren't wildly exploited at this very moment, nor have been for quite some time, we can pretty confidently claim there are no browser RCEs in wide use today.
It's true that browsers have pretty big attack surface, but it's also true that it's the class of software that gets the more pentesting, since the payoff would be so great when you manage to find holes.