# Business Logic Input Validation

- ID: go-business-logic-input-validation
- Severity: MEDIUM
- CWE: Improper Input Validation (CWE-20)
- Languages: Go

## Description

Business-critical values (discount, quantity, refund) used without validation.

## Detection Message

Business-critical value used without proper validation

## Remediation

Parse and validate business-critical values before use.

```go
discount, err := strconv.ParseFloat(r.FormValue("discount"), 64)
if err != nil || discount < 0 || discount > 100 {
    http.Error(w, "Invalid discount", 400)
    return
}
```

Learn more: https://shoulder.dev/learn/go/cwe-20/input-validation

## Related Rules

- **FastAPI Missing Request Validation** [MEDIUM]: 
- **Echo Missing Input Validation** [MEDIUM]: 
- **Fiber Missing Input Validation** [MEDIUM]: 
- **Gin Missing Input Validation** [MEDIUM]: 
- **Business Logic Input Validation** [MEDIUM]: