NaCL is a good example that shows how inspecting code is not actually the mistake that was made by the Python sandbox that was attacked in the article. The mist

NaCL is a good example that shows how inspecting code is not actually the mistake that was made by the Python sandbox that was attacked in the article. The mistake was that the inspection was based on a blacklist rather than a whitelist. Sandboxing based on blacklists is a recipe for disaster, and it's an unfortunate accident of history that the default Python implementation (CPython) makes whitelisting practically impossible. Luckily, there are alternatives as others in the thread have pointed out.