> Surely any script involving the hijacking of `[`
It's not about hijacking of any binary, it's about mutation of state, and having to keep the same parsing state across multiple binaries, which is very bad practice (apart from USR1/2 and stdout/stdin not even remotely being made for that).
Keep in mind that the architecture we are speaking about was implemented when an OS had less than 20 binaries overall.
Now we have thousands of binaries with absurd levels of complexity, and nobody really knows what's going on anymore.
This still seems very handwavey to me with respect to the actual vulnerabilities. And the only 'split parsing' going on is external commands parsing arguments passed to them. `test` doesn't parse bash or any other shell. `[` is not special, either; it doesn't have to communicate anything back to the shell invoking it about how to parse the rest of the program, either!
Are you categorically against shell scripting (the invocation of external binaries as commands), then?
It's not about hijacking of any binary, it's about mutation of state, and having to keep the same parsing state across multiple binaries, which is very bad practice (apart from USR1/2 and stdout/stdin not even remotely being made for that).
Keep in mind that the architecture we are speaking about was implemented when an OS had less than 20 binaries overall.
Now we have thousands of binaries with absurd levels of complexity, and nobody really knows what's going on anymore.