Bola Idor in Fiber

BOLA/IdOR (Broken Object Level Authorization / Insecure Direct Object Reference) vulnerabilities in Fiber applications typically emerge through the framework's flexible routing and parameter handling. Fiber's design philosophy emphasizes developer productivity, which can inadvertently lead to authorization gaps when objects are referenced directly by ID without proper ownership validation.

The most common pattern appears in resource retrieval endpoints where developers use URL parameters to fetch database records. Consider a typical Fiber route:

app.Get("/api/users/:id", func(c *fiber.Ctx) error {
    id := c.Params("id")
    user := getUserByID(id) // No authorization check
    return c.JSON(user)
})

This seemingly innocuous code exposes a critical vulnerability. An authenticated user can modify the :id parameter to access any user's data, regardless of whether they own that resource. The vulnerability stems from Fiber's efficient parameter binding system, which makes it trivial to access request parameters but doesn't enforce any authorization logic by default.

Another Fiber-specific manifestation occurs with the framework's automatic JSON binding capabilities. When handling POST/PUT requests:

app.Put("/api/users/:id", func(c *fiber.Ctx) error {
    id := c.Params("id")
    var updateData map[string]interface{}
    if err := c.BodyParser(&updateData); err != nil {
        return err
    }
    updateUser(id, updateData) // No ownership verification
    return c.JSON(fiber.Map{"status": "updated"})
})

The combination of URL parameter extraction and automatic body parsing creates a perfect storm for BOLA/IdOR vulnerabilities. Fiber's design makes it exceptionally easy to write concise, functional code, but this convenience can mask critical security gaps.

Database query patterns in Fiber applications often exacerbate these vulnerabilities. Using GORM or similar ORMs:

app.Get("/api/orders/:orderID", func(c *fiber.Ctx) error {
    orderID := c.Params("orderID")
    order := Order{}
    db.First(&order, orderID) // Returns any order by ID
    return c.JSON(order)
})

Without ownership checks, any authenticated user can enumerate order IDs and access other customers' order data. Fiber's middleware architecture, while powerful, requires explicit implementation of authorization checks rather than providing them by default.

Collection endpoints present another vulnerability vector:

app.Get("/api/users/:userID/orders", func(c *fiber.Ctx) error {
    userID := c.Params("userID")
    orders := getOrdersByUserID(userID) // No current user validation
    return c.JSON(orders)
})

An attacker can simply change the userID parameter to view any user's order history, exploiting Fiber's straightforward parameter handling.

Detecting BOLA/IdOR vulnerabilities in Fiber applications requires systematic testing of parameter handling and authorization logic. The most effective approach combines automated scanning with manual verification of critical endpoints.

middleBrick's Fiber-specific scanning capabilities excel at identifying these vulnerabilities through black-box testing methodology. The scanner automatically generates test sequences that modify URL parameters and request bodies to probe for unauthorized data access. For a typical Fiber endpoint like:

app.Get("/api/products/:productID", func(c *fiber.Ctx) error {
    productID := c.Params("productID")
    product := getProductFromDB(productID)
    return c.JSON(product)
})

middleBrick will systematically test parameter manipulation patterns, attempting to access products with IDs that the authenticated user shouldn't own. The scanner's intelligence extends to recognizing Fiber's common patterns, including automatic JSON binding and parameter extraction methods.

Manual detection techniques complement automated scanning. Key indicators of potential BOLA/IdOR vulnerabilities in Fiber applications include:

• Endpoints that directly use URL parameters without authorization checks
• Database queries that retrieve records by ID without ownership validation
• Collection endpoints that accept user IDs as parameters
• Update operations that don't verify resource ownership

middleBrick's comprehensive scanning approach tests all 12 security categories, with specific attention to authentication bypass attempts and authorization flaws. The scanner's 5-15 second analysis time makes it practical to integrate into development workflows, allowing teams to catch vulnerabilities before deployment.

For Fiber applications using JWT authentication, middleBrick tests whether tokens are properly scoped and whether endpoints respect token claims. The scanner attempts parameter manipulation even when valid authentication tokens are provided, revealing whether authorization logic is properly implemented.

middleBrick's OpenAPI/Swagger analysis capability is particularly valuable for Fiber applications, as it can cross-reference API specifications with actual runtime behavior. This helps identify discrepancies between documented security requirements and implemented functionality.

Remediating BOLA/IdOR vulnerabilities in Fiber applications requires implementing robust authorization checks throughout the codebase. The most effective approach leverages Fiber's middleware system to create reusable authorization logic.

Start by creating a middleware that validates resource ownership:

func authorizeResource(next fiber.Handler, getResourceOwner func(string) (string, error)) fiber.Handler {
    return func(c *fiber.Ctx) error {
        resourceID := c.Params("id")
        ownerID, err := getResourceOwner(resourceID)
        if err != nil || ownerID != c.Locals("userID") {
            return c.Status(fiber.StatusForbidden).JSON(fiber.Map{
                "error": "Access denied",
            })
        }
        return next(c)
    }
}

// Usage
app.Get("/api/users/:id", authorizeResource(getUserOwner, func(c *fiber.Ctx) error {
    return c.Next()
}))

This pattern ensures that users can only access resources they own. The getResourceOwner function should query the database to verify ownership relationships.

For collection endpoints, implement similar ownership verification:

app.Get("/api/users/:userID/orders", func(c *fiber.Ctx) error {
    userID := c.Params("userID")
    currentUserID := c.Locals("userID").(string)
    
    if userID != currentUserID {
        return c.Status(fiber.StatusForbidden).JSON(fiber.Map{
            "error": "Cannot access other users' orders",
        })
    }
    
    orders := getOrdersByUserID(userID)
    return c.JSON(orders)
})

middleBrick's remediation guidance emphasizes the principle of