Comment by deathanatos

Well, so there's two other problems with system (and popen):

1. IME security teams want to run dumb linters over the code that look for such things. While uses such as the ones you describe are secure, the linter might be blunter than that. I'm not sure that's necessarily a bad thing: "this use of system(3) is secure" has a cognitive tax at review time, and as the code changes; often, I prefer the stance of "don't make me think" with regards to security: i.e., do the simple, trivially secure thing, not the complex, secure under the just-right conditions thing. Then we don't have to persuade (potentially non-technical) security teams, non-technical auditors, linters, etc. that are going over the code with blunt instruments.

2. (And much more minor) the entire execution of sh is often just wasted performance that an exec(2) removes.

(& yes, you are also right that even an exec(2), mishandled, can have its problems in some circumstances. But typically when the pattern is system("<shell that just runs what we'd exec(2)>"), then whatever those problems are, system(3) is going to share them.)