Broken Access Control in Buffalo with Cockroachdb

Broken Access Control in a Buffalo application using Cockroachdb typically arises when authorization checks are missing or incorrectly applied before database operations. Buffalo encourages building handlers that interact with models, and if those handlers do not validate that the current user is permitted to access or modify a specific record, an attacker can manipulate identifiers (IDs) to access or alter data that should be restricted. Cockroachdb, as a distributed SQL database, stores records with primary keys that are often exposed directly in URLs or API endpoints. When Buffalo routes like /accounts/:id pass the raw :id to a query without verifying ownership or scope, the unauthenticated or low-privilege actor can perform Insecure Direct Object References (IDOR), a common manifestation of Broken Access Control.

Consider a scenario where a Buffalo handler retrieves an account record using Cockroachdb without confirming that the authenticated user is allowed to view that account:

// handlers/accounts.go
func AccountsShow(c buffalo.Context) error {
  id := c.Param("id")
  var account Account
  if err := db.Get(c.Request().Context(), &account, "SELECT * FROM accounts WHERE id = $1", id); err != nil {
    return c.Error(500, err)
  }
  return c.Render(200, r.H{"account": account})
}

In this example, the handler trusts the id from the URL and queries Cockroachdb directly. There is no check that the authenticated user owns or is authorized to view this account. An attacker can iterate through numeric or predictable IDs to enumerate accounts, which maps to the OWASP API Top 10 Broken Object Level Authorization (BOLA) / IDOR. Because Cockroachdb enforces SQL constraints but does not enforce application-level permissions, the vulnerability exists in the Buffalo layer, not the database itself. The scan category BOLA/IDOR under middleBrick’s checks would flag this as a high-severity finding, and the Data Exposure check might also detect that sensitive fields are returned without proper masking or authorization.

Additionally, if the Buffalo application uses role-based checks but places them after the database query, or uses raw SQL with concatenated identifiers, the risk increases. Cockroachdb’s strong consistency means that once an unauthorized query is executed, data is returned immediately, enabling attackers to exfiltrate PII or modify records depending on the user’s effective permissions. middleBrick’s BFLA/Privilege Escalation and Property Authorization checks are designed to detect such misplacements in authorization logic. Using unauthenticated scans, middleBrick can identify endpoints that expose sensitive endpoints without requiring credentials, highlighting the need for explicit authorization before data retrieval or mutation.

To remediate Broken Access Control in Buffalo with Cockroachdb, enforce authorization before any database interaction and use parameterized queries to avoid injection while ensuring that every query respects the user’s scope. Prefer scoped queries that include the user identifier as part of the filter, rather than fetching a record and then checking permissions in application code.

Below is a secure version of the previous handler, where the current user’s ID is obtained from the session and enforced in the SQL predicate:

// handlers/accounts.go
func AccountsShow(c buffalo.Context) error {
  userID := c.Value("user_id").(int64) // obtained from session or JWT
  id := c.Param("id")
  var account Account
  // Ensure the account belongs to the requesting user
  if err := db.Get(c.Request().Context(), &account,
    "SELECT * FROM accounts WHERE id = $1 AND user_id = $2", id, userID); err != nil {
    if errors.Is(err, sql.ErrNoRows) {
      return c.Error(403, errors.New("access denied"))
    }
    return c.Error(500, err)
  }
  return c.Render(200, r.H{"account": account})
}

This approach guarantees that even if an attacker modifies the id parameter, Cockroachdb will return no rows unless the record both matches the ID and belongs to the authenticated user. The 403 response is returned for missing or unauthorized records, avoiding information leakage via 404 differences.

For list endpoints, apply the same scoping principle:

// handlers/accounts.go
func AccountsIndex(c buffalo.Context) error {
  userID := c.Value("user_id").(int64)
  var accounts []Account
  if err := db.Select(c.Request().Context(), &accounts,
    "SELECT id, name, email FROM accounts WHERE user_id = $1", userID); err != nil {
    return c.Error(500, err)
  }
  return c.Render(200, r.H{"accounts": accounts})
}

By pushing authorization into the WHERE clause, you reduce the attack surface and ensure that Cockroachdb only returns rows the user is allowed to see. middleBrick’s Authorization and Authentication checks can validate that such controls are present and that endpoints do not leak data when credentials are omitted.

Finally, avoid dynamic SQL construction that interpolates identifiers or roles directly into queries. Use prepared statements and parameterized queries to prevent injection while preserving the correctness of access controls. Regular scans with the middleBrick CLI can help confirm that remediation is effective and that no regressions introduce missing checks.