Cross Site Request Forgery in Fiber with Cockroachdb

Cross Site Request Forgery (CSRF) in a Fiber application that uses CockroachDB can occur when state-changing requests rely solely on cookies for authentication without additional anti-CSRF controls. Because CockroachDB is a distributed SQL database, it does not provide built-in CSRF protections; it faithfully executes SQL statements issued by the application. If a Fiber route constructs SQL queries using string concatenation or improper parameter handling, an attacker can trick a victim’s browser into sending crafted requests that execute unintended database operations.

Consider a Fiber endpoint that updates a user’s email by reading an unvalidated JSON parameter and interpolating it into a SQL string. An attacker can host a malicious page that sends a POST request to this endpoint while the user’s session cookie is present. Because CockroachDB does not distinguish between requests initiated by the user and those initiated by an attacker, it will apply the SQL statement with the attacker-supplied values. This becomes especially risky when the application uses session cookies without SameSite attributes or CSRF tokens, as the browser will automatically include credentials in cross-origin requests.

The combination of Fiber’s lightweight routing and CockroachDB’s strong consistency can amplify the impact: a single malicious request can perform writes in the correct database transaction context, potentially bypassing simplistic authorization checks that only verify user ID presence. For example, if an endpoint uses a URL parameter like userID to determine whose data to update, an attacker can forge a request with any userID value. Because CockroachDB transactions are explicit in the application code, the vulnerability depends on how the application builds and executes SQL rather than on the database itself.

Common patterns that increase CSRF risk include skipping anti-CSRF middleware, relying on non-persistent headers for authorization, and exposing write endpoints that accept JSON or form data without verifying request origin. Even when using prepared statements with CockroachDB, if the application logic does not validate the origin of the request, the database will still execute the intended mutation with attacker-supplied data. This aligns with OWASP API Top 10’s Broken Object Level Authorization and Security Misconfiguration risks, and can map to compliance frameworks such as PCI-DSS and SOC2 when sensitive data is involved.

To detect such issues, middleBrick scans unauthenticated attack surfaces and can identify endpoints that accept state-changing methods without CSRF-relevant protections. The tool cross-references OpenAPI specifications with runtime behavior, highlighting missing anti-CSRF mechanisms and overly permissive CORS or cookie settings. While middleBrick provides findings and remediation guidance, it does not fix or block requests; developers must implement appropriate defenses in their Fiber application.

Remediation focuses on ensuring that every state-changing request is authenticated and authorized with additional safeguards, independent of the database’s behavior. In Fiber, apply consistent anti-CSRF practices such as synchronizer token patterns, strict SameSite cookie attributes, and CORS policies. Use parameterized SQL with CockroachDB to avoid injection, and validate all inputs before constructing queries.

Example secure Fiber handler with CockroachDB using the pgx driver and a CSRF token verified from a custom header:

// Assume a middleware sets req.Locals("csrfToken") after validating a per-session token
func UpdateUserEmail(c *fiber.Ctx) error {
    userID := c.Params("userID")
    // Validate userID format before using it
    if !isValidUserID(userID) {
        return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "invalid userID"})
    }

    var body struct {
        Email string `json:"email"`
        CsrfToken string `json:"csrf_token"`
    }
    if err := c.BodyParser(&body); err != nil {
        return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{"error": "invalid body"})
    }

    // Verify CSRF token provided in request body or header matches session token
    sessionToken := string(c.Locals("csrfToken").(string))
    if body.CsrfToken != sessionToken {
        return c.Status(fiber.StatusForbidden).JSON(fiber.Map{"error": "invalid CSRF token"})
    }

    conn, err := pgx.Connect(context.Background(), os.Getenv("COCKROACHDB_URL"))
    if err != nil {
        return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{"error": "database connection failed"})
    }
    defer conn.Close(context.Background())

    // Use parameterized query to avoid SQL injection
    _, err = conn.Exec(context.Background(),
        "UPDATE users SET email = $1 WHERE id = $2",
        body.Email, userID)
    if err != nil {
        return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{"error": "update failed"})
    }

    return c.JSON(fiber.Map{"message": "email updated"})
}

Key points in this example:

• CSRF token validation occurs before any database interaction, ensuring requests originate from the expected client.
• userID is validated for format to prevent path traversal or ID manipulation beyond expected patterns.
• Parameterized SQL with $1 and $2 placeholders ensures CockroachDB treats values strictly as data, not executable code.
• CockroachDB receives clean, pre-validated inputs; the database does not need CSRF awareness because the application layer enforces request integrity.

Additional recommendations include setting SameSite=Strict or Lax on session cookies, enforcing HTTPS, and using CORS policies that limit origins. middleBrick can help identify missing CSRF protections and cookie attributes during scans, supporting compliance mapping to frameworks such as OWASP API Top 10 and SOC2. Continuous monitoring with the Pro plan or automated checks in CI/CD via the GitHub Action can catch regressions before deployment.