Broken Access Control in Echo Go with Basic Auth

Broken Access Control occurs when authorization checks are missing or bypassed, allowing authenticated users to access or modify resources that should be restricted. In Echo Go, pairing Basic Auth with insufficient route-level authorization is a common pattern that exposes this vulnerability.

When Basic Auth is used without explicit role or scope checks, any user who supplies valid credentials can reach endpoints that should be limited to administrators or specific tenant contexts. For example, an authenticated user might call an admin-only endpoint such as /admin/reset or access another user’s data via an IDOR-prone route like /users/:id. Because Basic Auth transmits credentials in an easily decoded header, compromised credentials amplify the risk: an attacker who obtains a base64-encoded token can replay requests to privileged paths.

Echo Go handlers often omit granular permission checks when developers assume HTTP authentication is sufficient. Consider an endpoint that lists all users:

e.GET("/users", func(c echo.Context) error {
    users, err := store.ListUsers()
    if err != nil {
        return echo.NewHTTPError(http.StatusInternalServerError)
    }
    return c.JSON(http.StatusOK, users)
})

If this handler lacks a check like isAdmin, any authenticated user can enumerate the full user directory. In a microservice environment where Echo Go services are exposed directly, missing authorization at the handler level means the service trusts the caller once credentials are validated. This aligns with the BOLA/IDOR category in middleBrick’s checks, where predictable IDs and missing ownership validation enable horizontal privilege escalation. middleBrick’s 12 security checks run in parallel and would flag this as a high-severity finding under the Authorization and Authentication categories, noting that valid credentials do not imply valid authorization.

Additionally, Basic Auth does not provide scopes or roles natively. Without implementing group or role claims, Echo Go developers must enforce RBAC or ABAC manually. A missing middleware that verifies claims or group membership creates a gap where an authenticated non-admin can perform admin actions. This is especially critical when OpenAPI specs declare security schemes but omit securityRequirements for specific paths, causing runtime behavior to diverge from documented expectations. middleBrick’s OpenAPI/Swagger analysis would cross-reference spec definitions with runtime findings to highlight such inconsistencies.

Remediation centers on adding explicit authorization checks after authentication and avoiding implicit trust in Basic Auth credentials. Below are concrete, working examples for Echo Go that you can apply directly.

1. Role-based guard with middleware

Create a middleware that validates a role claim extracted from a verified identity. This example assumes you enrich the context with user claims after Basic Auth validation.

func RequireRole(role string) echo.MiddlewareFunc {
    return func(next echo.HandlerFunc) echo.HandlerFunc {
        return func(c echo.Context) error {
            u, ok := c.Get("user").(*User)
            if !ok || u.Role != role {
                return echo.NewHTTPError(http.StatusForbidden, "insufficient permissions")
            }
            return next(c)
        }
    }
}

// Usage
admin := RequireRole("admin")
e.GET("/admin/reset", admin, func(c echo.Context) error {
    // admin-only logic
    return c.NoContent(http.StatusOK)
})

2. Ownership check for user-specific resources

For endpoints like /users/:id, ensure the requesting user owns the resource or has explicit rights.

func CanAccessUser(c echo.Context, requestedID string) bool {
    user, ok := c.Get("user").(*User)
    if !ok {
        return false
    }
    // Owners can access their own profile
    if user.ID == requestedID {
        return true
    }
    // Admins can access any profile
    if user.Role == "admin" {
        return true
    }
    return false
}

e.GET("/users/:id", func(c echo.Context) error {
    id := c.Param("id")
    if !CanAccessUser(c, id) {
        return echo.NewHTTPError(http.StatusForbidden, "access denied")
    }
    u, err := store.GetUser(id)
    if err != nil {
        return echo.NewHTTPError(http.StatusNotFound, "not found")
    }
    return c.JSON(http.StatusOK, u)
})

3. Combine Basic Auth with scope validation

If you issue tokens or session values that include scopes, validate them before proceeding.

func RequireScope(required string) echo.MiddlewareFunc {
    return func(next echo.HandlerFunc) echo.HandlerFunc {
        return func(c echo.Context) error {
        claims, ok := c.Get("claims").(jwt.MapClaims)
        if !ok {
            return echo.NewHTTPError(http.StatusForbidden, "invalid claims")
        }
        scopes, ok := claims["scope"].([]interface{}) // or string split
        if !ok || !contains(scope, required) {
            return echo.NewHTTPError(http.StatusForbidden, "scope required")
        }
        return next(c)
    }
}

func contains(s []interface{}, target string) bool {
    for _, v := range s {
        if v == target {
            return true
        }
    }
    return false
}

4. Use middleBrick to validate your configuration

After implementing fixes, you can verify your changes with middleBrick. The CLI tool allows you to scan from the terminal:

middlebrick scan https://api.example.com/openapi.json

The dashboard lets you track scores over time, and the Pro plan’s continuous monitoring can schedule regular scans so regressions are caught early. The GitHub Action adds API security checks to your CI/CD pipeline, failing builds if the risk score drops below your chosen threshold. For AI-assisted development, the MCP Server integrates middleBrick into editors like Claude and Cursor so you can scan APIs directly from your IDE.