allowlist WASI features/interfaces

[neuronicnobody]

allowlist WASI features/interfaces

[bhelx]

Not sure i can give a completely general answer, but in the given scenario, you shouldn't be able to access the filesystem just because you have WASI enabled. You still need to explicitly map which directories the guest can access. Same goes for the networking resources. You should be blocked by default unless the host explicitly says which domains can be accessed.

[neuronicnobody]

Talked to a few others on this as well and here's a bit more detail:

By default, when you use WASI in Extism you can really only access the clock and a random entropy without further explicit grants by the host. If the host doesn't specify allowed_hosts or allowed_paths, then no network or filesystem access is granted. Extism does not currently have a way to disable clock or rand access.

Modsurfer can be a good helper tool in this situation as it provides an automated way to scan any plugins before runtime and confirm that they don't import certain undesirable WASI functions.