Craft Commerce: Coupon Code Brute-Force via Rate Limit Bypass

Description

### Summary The CartController defines a RateLimiter behavior that is only activated when the 'number' POST/GET parameter is explicitly provided. ### Details When an attacker submits coupon codes against the session-based cart (without passing a 'number' parameter), no rate limiting is applied. This allows unlimited attempts to guess coupon codes. **Vulnerable Code** <img width="864" height="90" alt="resim" src="https://github.com/user-attachments/assets/a5197f10-f1fd-4331-93f9-9479d0ceebba" /> <img width="881" height="272" alt="resim" src="https://github.com/user-attachments/assets/d9db963f-5d1f-4b00-a4b4-5f2dfe2b71dd" /> <img width="861" height="271" alt="resim" src="https://github.com/user-attachments/assets/f7842493-3bc0-4e99-956c-7266bab15703" /> ### PoC Complete instructions, including specific configuration details, to reproduce the vulnerability. <img width="909" height="171" alt="resim" src="https://github.com/user-attachments/assets/cfc8c994-5e0c-48de-b728-464029beba0e" /> ### Impact An attacker can enumerate all coupon codes through automated requests. **Remediation** Apply rate limiting unconditionally on actionUpdateCart regardless of whether 'number' is present.

Affected Packages (1)