You don’t need to prove that no input can crash the code. “Exhaustive testing is not possible” is one of the core testing principles, ISTQB teaches that. As far as we know, the input was a file filled with zeroes, and not some subtle configuration or instruction. That can definitely be expected, tested, and handled.
As far as we know, the input was a file filled with zeroes
CrowdStrike have said that was not the problem:
This is not related to null bytes contained within Channel File 291 or any other Channel File.
That said, their preliminary incident review doesn’t give us much to go on as to what was wrong with the file.
You’re speculating that it was something easy to test for by a third party. It certainly could have been but I would hope it’s a more subtle bug which, as you say, can’t be exhaustively tested for. Source code analysis definitely would have surfaced this bug so either they didn’t bother looking or didn’t bother fixing it.
