Insecure Direct Object Reference in Aspnet with Cockroachdb

Insecure Direct Object Reference (IDOR) occurs when an API exposes a reference to a resource (such as a database row) without enforcing that the authenticated subject has permission to access that specific instance. In an Aspnet application using Cockroachdb as the backing store, the risk emerges from coupling predictable object references—often integer or UUID primary keys—with authorization checks that are missing or applied inconsistently.

Consider an endpoint like /api/users/{userId} that retrieves profile data from a Cockroachdb table. If the route value userId is taken directly from the request and used to form a SQL query such as SELECT * FROM users WHERE id = $1, the database will return the record if it exists, but the application may never verify whether the requesting user is allowed to view that row. Because Cockroachdb preserves row order and exposes stable keys across nodes, an attacker can iterate through numeric or sequential identifiers and enumerate other users’ data without triggering server-side access controls. Aspnet’s model binding will map the route parameter to an int or Guid, and if the developer relies solely on route validation or simplistic claim checks (e.g., requiring a role but not scoping to the resource), the unauthenticated or low-privilege attacker can traverse relationships that the database happily serves.

The use of Cockroachdb can inadvertently amplify the exposure. Cockroachdb’s distributed SQL layer returns rows for a given primary key efficiently, and if the Aspnet data access layer does not inject tenant or ownership predicates into every query, a request for /api/accounts/123 might resolve to a row in a different tenant or organization. Without additional filters—such as a tenant_id column validated on each request—the database treats the identifier as globally unique and returns data, even when the caller’s context does not match. This becomes especially relevant in multi-tenant setups where row-level security (RLS) is not enforced at the database level and authorization is implemented only in application code that may be inconsistently applied across endpoints.

Real-world attack patterns mirror the OWASP API Top 10 A01:2023 broken access control, often intersecting with IDOR when object references are predictable. In a Cockroachdb-backed Aspnet service, an attacker might capture a valid resource identifier from network traffic or logs and then substitute it in crafted requests. Because the database schema may expose foreign-key relationships (e.g., orders.customer_id), traversing these links with modified IDs can lead to privilege escalation or data exfiltration. The scanner’s BOLA/IDOR checks, combined with property-level authorization tests, are designed to detect these gaps by correlating spec definitions with runtime behavior, highlighting endpoints where identifiers are accepted without proper ownership or scope validation.

Remediation centers on ensuring that every data access path in Aspnet includes explicit, context-aware authorization and tenant scoping before forming queries against Cockroachdb. Below are concrete patterns using parameterized SQL with Npgsql, demonstrating how to bind both the resource identifier and the requester’s context.

1. Scope queries by tenant and ownership

Always include a tenant or owner predicate in the WHERE clause, derived from the current user’s claims, and use parameters to avoid injection.

// Example using Npgsql with Aspnet and Cockroachdb
public async Task<UserProfile> GetUserProfileAsync(int userId, ClaimsPrincipal user)
{
    // Extract tenant from claims or a subdomain mapping
    if (!user.FindFirst("tenant_id")?.Value is string tenantId || !Guid.TryParse(tenantId, out var tenant))
        throw new SecurityException("Tenant not resolved");

    await using var conn = new NpgsqlConnection(_connectionString);
    await conn.OpenAsync();
    await using var cmd = new NpgsqlCommand(
        "SELECT id, display_name, email FROM users WHERE id = $1 AND tenant_id = $2 AND owner_id = $3 LIMIT 1",
        conn);
    cmd.Parameters.AddWithValue(userId);
    cmd.Parameters.AddWithValue(tenant);
    cmd.Parameters.AddWithValue(user.FindFirst("sub")?.Value);

    await using var reader = await cmd.ExecuteReaderAsync();
    if (!await reader.ReadAsync())
        return null;

    return new UserProfile
    {
        Id = reader.GetInt32(0),
        DisplayName = reader.GetString(1),
        Email = reader.GetString(2)
    };
}

2. Use row-level security where possible

Define RLS policies in Cockroachdb so that even if an identifier leaks, the database enforces tenant boundaries. Then ensure Aspnet still passes the requester’s identity to the driver so session-based policies (if used) align.

-- Cockroachdb DDL example
ALTER TABLE users ENABLE ROW LEVEL SECURITY;
CREATE POLICY tenant_isolation ON users
  FOR SELECT
  USING (tenant_id = current_setting('app.tenant_id')::uuid AND owner_id = current_setting('app.user_id')::uuid);

Set the session parameters from Aspnet before executing user queries:

await using var conn = new NpgsqlConnection(_connectionString);
await conn.OpenAsync();
await using var cmd = conn.CreateCommand();
cmd.CommandText = @"
  SET app.tenant_id = $1;
  SET app.user_id = $2;
  SELECT id, display_name FROM users WHERE id = $3;
";
cmd.Parameters.AddWithValue(tenantId);
cmd.Parameters.AddWithValue(userId);
cmd.Parameters.AddWithValue(requestedUserId);
await using var reader = await cmd.ExecuteReaderAsync();

3. Validate and scope list endpoints

When endpoints return collections (e.g., /api/orders), ensure filters include tenant and ownership, and use offset/limit with server-side paging keys rather than client-supplied indirect references.

public async Task<List<Order>> ListOrdersForTenantAsync(ClaimsPrincipal user, int page = 1, int pageSize = 20)
{
    var tenantId = user.FindFirst("tenant_id")?.Value ?? throw new SecurityException("Tenant missing");
    var userId = user.FindFirst("sub")?.Value ?? throw new SecurityException("User missing");

    await using var conn = new NpgsqlConnection(_connectionString);
    await conn.OpenAsync();
    await using var cmd = new NpgsqlCommand(
        @"SELECT id, total, status FROM orders WHERE tenant_id = $1 AND (requester_id = $2 OR is_public = TRUE) ORDER BY created_at DESC LIMIT $3 OFFSET $4",
        conn);
    cmd.Parameters.AddWithValue(tenantId);
    cmd.Parameters.AddWithValue(userId);
    cmd.Parameters.AddWithValue(pageSize);
    cmd.Parameters.AddWithValue((page - 1) * pageSize);

    var orders = new List<Order>();
    await using var reader = await cmd.ExecuteReaderAsync();
    while (await reader.ReadAsync())
    {
        orders.Add(new Order
        {
            Id = reader.GetInt32(0),
            Total = reader.GetDecimal(1),
            Status = reader.GetString(2)
        });
    }
    return orders;
}

By embedding tenant and ownership checks directly in the SQL and using Cockroachdb’s parameter support, Aspnet applications can neutralize predictable ID traversal. These patterns align with the scanner’s checks for BOLA/IDOR and property authorization, ensuring that object references are never interpreted without contextual authorization.