While I've used c-reduce before, I've never done it in a way where it could be destructive. However speculating based on what I do know. I think the 2 things I would do would be in the interesting-ness test, grep for already known harmful instructions and force them to be uninteresting (returning 1). And then if I was still unsure of the potential harm of the program and I had to run it to determine if it's interesting or not (segfault or something similar). I think I would hoist the binary/script into a docker container and run it there. That way the log and result can still be checked, but it's access to actual file system is minimized as much as possible.
TLDR; C-Reduce just gives you text to run/compile, if you're worried about things like that sandbox as much as possible.
TLDR; C-Reduce just gives you text to run/compile, if you're worried about things like that sandbox as much as possible.