Fix SQL Injection (Legacy & Modern) in Buffalo

Buffalo's pop ORM is a solid abstraction, but developers frequently bypass its safety features by resorting to raw SQL or improper string formatting. If you're using fmt.Sprintf or string concatenation to build queries, you're inviting a blind SQLi or data exfiltration. In the Buffalo ecosystem, safety is achieved through parameter binding—no exceptions.

The Vulnerable Pattern

func (v UsersResource) Show(c buffalo.Context) error {
	query := fmt.Sprintf("SELECT * FROM users WHERE id = '%s'", c.Param("id"))
	user := models.User{}
	err := models.DB.RawQuery(query).First(&user)
	if err != nil {
		return c.Error(404, err)
	}
	return c.Render(200, r.JSON(user))
}

The Secure Implementation

The vulnerability stems from treating user-controlled input as executable SQL code. By using fmt.Sprintf, the input is concatenated directly into the query string, allowing an attacker to break out of the quote context. The fix utilizes Pop's built-in parameterization. When you pass arguments to .Where() or .RawQuery() after the string template, the underlying database driver (pgx, mysql, etc.) handles the sanitization and ensures the input is treated strictly as a literal value, neutralizing the injection vector.

func (v UsersResource) Show(c buffalo.Context) error {
	user := models.User{}
	// Modern Buffalo/Pop approach: Use internal QueryBuilder with placeholders
	err := models.DB.Where("id = ?", c.Param("id")).First(&user)
// Legacy Raw approach: Still secure using positional arguments
// err := models.DB.RawQuery("SELECT * FROM users WHERE id = ?", c.Param("id")).First(&user)

if err != nil {
	return c.Error(404, err)
}
return c.Render(200, r.JSON(user))
}