In many versions of the "Moan Shop" challenge, the vulnerability is .

Crafts a malicious POST request to pollute the server’s environment.

Issues in how the "shopping cart" or "payment" logic handles quantities or prices. 2. The Critical Flaw: Prototype Pollution

An attacker sends a JSON payload containing the __proto__ key. This allows them to inject properties into the global object prototype, effectively changing the behavior of the entire application. 3. From Pollution to Remote Code Execution (RCE)

Once the attacker can "pollute" the global object, they target specific application behaviors to gain control: