Bola Idor in Echo Go with Basic Auth

Broken Object Level Authorization (BOLA) occurs when an API fails to enforce authorization checks on individual resource identifiers, allowing one user to access or modify another user's data. In Echo Go, using HTTP Basic Auth for identity without implementing per-request object ownership checks is a common pattern that can expose BOLA. Basic Auth provides authentication—verifying who is making the request—but it does not provide authorization context about what that user is allowed to access.

Consider an Echo Go handler that retrieves a user profile by ID from the URL path, validates the presence of Basic Auth credentials, and returns the profile without confirming the authenticated user owns that profile ID:

func getUserProfile(c echo.Context) error {
    // Extract Basic Auth credentials
    user, pass, ok := c.Request().BasicAuth()
    if !ok {
        return c.JSON(http.StatusUnauthorized, map[string]string{"error": "missing credentials"})
    }
    // Validate credentials (simplified)
    if !isValidUser(user, pass) {
        return c.JSON(http.StatusUnauthorized, map[string]string{"error": "invalid credentials"})
    }
    // Extract requested profile ID from path
    profileID := c.Param("id")
    var profile Profile
    // Direct lookup by ID without ownership check
    if db.Where(&Profile{ID: profileID}).First(&profile).Error != nil {
        return c.JSON(http.StatusNotFound, map[string]string{"error": "profile not found"})
    }
    return c.JSON(http.StatusOK, profile)
}

In this example, the attacker can enumerate numeric or predictable profile IDs and read any profile in the system because the handler never verifies that the authenticated user (from Basic Auth) is the owner of the requested profile. The presence of Basic Auth creates a false sense of security: authentication is present, but object-level authorization is missing. This maps to common attack patterns such as IDOR and BOLA listed in the OWASP API Top 10, and scanners like middleBrick can detect these issues during unauthenticated or authenticated-style scans that analyze endpoint behavior and spec-to-runtime alignment.

When Basic Auth is used without scoping data access to the authenticated identity, the API surface includes endpoints that reveal sensitive data across users. For example, an endpoint like /api/v1/users/{id} that relies solely on path parameters and Basic Auth is vulnerable if the server does not enforce a rule such as "the user associated with the credentials must match the user ID in the path or query context." middleBrick checks include verifying that authorization logic references the authenticated subject and that responses differ for subjects without access, which helps identify missing BOLA controls.

Additionally, if the API exposes related endpoints (e.g., listing resources or performing actions on a resource) without tying those operations to the authenticated principal, the BOLA risk compounds. In distributed systems where multiple services share authentication information like Basic Auth headers, inconsistent authorization enforcement across services can further expose object-level vulnerabilities. Proper remediation requires binding the authentication context to each data access operation, ensuring that every object-level request includes a verifiable ownership or permission check tied to the authenticated identity.

To fix BOLA in Echo Go when using Basic Auth, ensure that every data access operation validates that the authenticated subject has permission to operate on the specific object. This means coupling the credentials extracted via Basic Auth with the resource identifier in the request, typically by including a user identifier in the path or by mapping credentials to a subject ID stored server-side.

One approach is to embed the user identifier in the URL path and enforce a match between the authenticated user and the path parameter. For example:

func getUserProfileSecure(c echo.Context) error {
    // Extract Basic Auth credentials
    user, pass, ok := c.Request().BasicAuth()
    if !ok {
        return c.JSON(http.StatusUnauthorized, map[string]string{"error": "missing credentials"})
    }
    if !isValidUser(user, pass) {
        return c.JSON(http.StatusUnauthorized, map[string]string{"error": "invalid credentials"})
    }
    // Derive subject ID from authenticated user (e.g., via a mapping table or JWT claims)
    subjectID, err := getUserSubjectID(user)
    if err != nil {
        return c.JSON(http.StatusUnauthorized, map[string]string{"error": "invalid subject"})
    }
    // Extract requested profile ID from path
    profileID := c.Param("id")
    // Enforce ownership: only allow access if subjectID matches profile owner
    var profile Profile
    if db.Where(&Profile{ID: profileID, UserID: subjectID}).First(&profile).Error != nil {
        return c.JSON(http.StatusForbidden, map[string]string{"error": "access denied to this resource"})
    }
    return c.JSON(http.StatusOK, profile)
}

In this secure pattern, getUserSubjectID maps the Basic Auth username to a stable subject identifier (such as a UUID), and the database query includes both the profile ID and the subject ID, ensuring that users can only access their own records. This aligns with the principle of binding authentication context to authorization decisions, which mitigates BOLA/IDOR risks.

For endpoints that accept identifiers in the request body or query parameters, apply the same ownership check before performing any operation. For example, when updating a resource:

func updateUserSettings(c echo.Context) error {
    user, pass, ok := c.Request().BasicAuth()
    if !ok {
        return c.JSON(http.StatusUnauthorized, map[string]string{"error": "missing credentials"})
    }
    if !isValidUser(user, pass) {
        return c.JSON(http.StatusUnauthorized, map[string]string{"error": "invalid credentials"})
    }
    subjectID, err := getUserSubjectID(user)
    if err != nil {
        return c.JSON(http.StatusUnauthorized, map[string]string{"error": "invalid subject"})
    }
    req := new(struct {
        Theme string `json:"theme"`
        Lang  string `json:"lang"`
    })
    if err := c.Bind(req); err != nil {
        return c.JSON(http.StatusBadRequest, map[string]string{"error": "invalid request"})
    }
    // Update only if the settings belong to the authenticated subject
    result := db.Model(&UserSettings{}).Where(&UserSettings{UserID: subjectID}).Updates(req)
    if result.Error != nil {
        return c.JSON(http.StatusInternalServerError, map[string]string{"error": "update failed"})
    }
    return c.JSON(http.StatusOK, map[string]string{"status": "updated"})
}

These examples demonstrate how to integrate Basic Auth with explicit object ownership checks. Using middleBrick’s scans can help verify that such checks exist at the handler level and that responses differ for subjects without access, supporting compliance mappings to frameworks like OWASP API Top 10 and SOC2 controls.