Insecure Design in Fiber with Cockroachdb

Insecure design in a Fiber service that uses CockroachDB often arises from trusting client-supplied identifiers to drive database operations without verifying authorization context. For example, an endpoint like /api/users/:userID/preferences may extract userID from the URL and directly build a CockroachDB query such as SELECT * FROM user_preferences WHERE user_id = $1 using that value. If the request does not enforce that the authenticated actor is the same subject as userID, an attacker can change the ID to access another user’s data. This is a Broken Object Level Authorization (BOLA) / IDOR pattern specific to the Fiber + CockroachDB stack because the database is the enforcement point and the application logic does not reconcile the request context with the supplied identifier.

Another insecure design pattern is missing ownership checks in multi-tenant workloads. CockroachDB’s SQL semantics support schemas and row-level controls, but if the Fiber app issues queries like SELECT * FROM documents WHERE id = $1 using only the document ID provided by the client, the application does not confirm that the document belongs to the requesting tenant or user. An attacker can iterate through IDs and read or modify data across tenants. Because CockroachDB is often deployed as a distributed SQL system, the risk is not limited to a single-node misconfiguration; the insecure design is in the application’s assumption that IDs alone are sufficient authorization proof.

Additionally, insecure design can appear in how the Fiber app structures transactions and retries. CockroachDB recommends explicit transaction boundaries and handling serialization errors, but an insecure design might open long-lived transactions or retry loops without considering contention and privilege implications. For instance, a Fiber handler that performs multiple writes based on unchecked client data can inadvertently apply changes at a higher privilege level if the session’s authentication is mismanaged. The combination of Fiber’s fast routing and CockroachDB’s strong consistency can mask these issues until an attacker exploits the missing authorization checks, making runtime scanning essential to surface these design gaps before deployment.

Remediation centers on enforcing ownership and tenant context in every database query and ensuring that the authenticated subject is validated server-side before constructing SQL. Below are concrete, CockroachDB-aware examples for Fiber in Go.

• Authenticated and scoped query with context and prepared statements:

// Good: scope by authenticated user ID, use context and parameterized queries
package main

import (
    "context"
    "github.com/gofiber/fiber/v2"
    "github.com/jackc/pgx/v5/pgxpool"
)

type UserPrefs struct {
    UserID    string `json:"user_id"`
    Theme     string `json:"theme"`
    Language  string `json:"language"`
}

func getUserPreferences(pool *pgxpool.Pool) fiber.Handler {
    return func(c *fiber.Ctx) error {
        // Obtain subject from authentication middleware; do not trust URL params alone
        subjectID := c.Locals("userID").(string)
        urlUserID := c.Params("userID")
        // Ensure the scoped subject matches the requested resource
        if subjectID != urlUserID {
            return c.Status(fiber.StatusForbidden).JSON(fiber.Map{"error": "access denied"})
        }
        ctx := c.Context()
        var prefs UserPrefs
        row := pool.QueryRow(ctx, "SELECT user_id, theme, language FROM user_preferences WHERE user_id = $1", subjectID)
        if err := row.Scan(&prefs.UserID, &prefs.Theme, &prefs.Language); err != nil {
            return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{"error": "unable to fetch preferences"})
        }
        return c.JSON(prefs)
    }
}

• Multi-tenant query with tenant ID from context, avoiding IDOR across tenants:

// Good: enforce tenant ownership on every CockroachDB query
package main

import (
    "context"
    "github.com/gofiber/fiber/v2"
    "github.com/jackc/pgx/v5/pgxpool"
)

type Document struct {
    ID        string `json:"id"`
    TenantID  string `json:"tenant_id"`
    Content   string `json:"content"`
}

func getDocument(pool *pgxpool.Pool) fiber.Handler {
    return func(c *fiber.Ctx) error {
        tenantID := c.Locals("tenantID").(string)
        docID := c.Params("docID")
        ctx := c.Context()
        var doc Document
        // Use parameterized query and tenant scope to prevent cross-tenant access
        row := pool.QueryRow(ctx, "SELECT id, tenant_id, content FROM documents WHERE id = $1 AND tenant_id = $2", docID, tenantID)
        if err := row.Scan(&doc.ID, &doc.TenantID, &doc.Content); err != nil {
            return c.Status(fiber.StatusNotFound).JSON(fiber.Map{"error": "document not found or access denied"})
        }
        return c.JSON(doc)
    }
}

• Transaction with explicit context and error handling to avoid long-lived sessions:

// Good: short-lived transaction with explicit rollback on error
package main

import (
    "context"
    "github.com/gofiber/fiber/v2"
    "github.com/jackc/pgx/v5/pgxpool"
)

func updateProfile(pool *pgxpool.Pool) fiber.Handler {
    return func(c *fiber.Ctx) error {
        subjectID := c.Locals("userID").(string)
        type updateReq struct {
            Email string `json:"email"`
        }
        var req updateReq
        if err := c.BodyParser(&req); err != nil {
            return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "invalid body"})
        }
        ctx := c.Context()
        tx, err := pool.Begin(ctx)
        if err != nil {
            return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{"error": "cannot start transaction"})
        }
        defer func() { _ = tx.Rollback(ctx) }()
        _, err = tx.Exec(ctx, "UPDATE profiles SET email = $1 WHERE user_id = $2", req.Email, subjectID)
        if err != nil {
            return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{"error": "update failed"})
        }
        if err := tx.Commit(ctx); err != nil {
            return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{"error": "commit failed"})
        }
        return c.SendStatus(fiber.StatusOK)
    }
}

These patterns ensure that the Fiber app does not rely on client-provided identifiers for authorization, that tenant boundaries are enforced at the query layer, and that CockroachDB transactions are short and explicitly managed. This addresses the insecure design by design rather than by runtime-only scanning.