Privilege Chaining

This vulnerability is like a security bypass puzzle. A system might correctly enforce that a user cannot directly delete a file or directly write to a system directory. However, if the user can first move a file into that protected directory (using one permission) and then delete any file they own there (using a second permission), they have effectively achieved an unauthorized deletion. The core failure is that the system's security checks evaluate each privilege in isolation, missing the dangerous sequence they enable when used together. To prevent this, developers must design authorization checks that consider context and history, not just the immediate action. This involves analyzing how privileges can interact over a session or transaction. Implementing mandatory access control (MAC), logging and monitoring for unusual privilege sequences, and adhering to the principle of least privilege are key defenses. Always ask: 'Could these two allowed actions be combined to achieve something we explicitly forbid?'