Lab: somebody else's order
An order viewer with no ownership check. Read order 102.
Read the viewer and confirm what it never asks. View your own order first for the baseline, then change the number: the server trusts the ID completely, and its answer tells you exactly whose data just leaked and for how much.
That was the whole lesson.
A free account adds the interactive part: the marking quiz, the lab if this lesson carries one, live progress, the timed exam, and a certificate employers can verify.