Bola Idor in Gin with Cockroachdb

Broken Object Level Authorization (BOLA) occurs when an API exposes internal object identifiers and lacks sufficient context-based authorization checks. In a Gin application using CockroachDB, this often maps to predictable primary key values in URL parameters such as /users/:id or /invoices/:invoice_id. Because CockroachDB is a distributed SQL database that reliably returns rows for existing keys, a request for /users/123 will return data if row 123 exists, regardless of whether the authenticated caller owns that row.

The Gin framework binds URL parameters into Go variables (e.g., id := strconv.Atoi(c.Param("id"))) and typically uses them in SQL queries like SELECT * FROM users WHERE id = $1. If the handler skips ownership validation—such as not verifying that the authenticated user’s ID matches the requested ID—BOLA is introduced. CockroachDB’s strong consistency means the query quickly confirms existence, making it trivial for an attacker to iterate numeric or UUID keys to access other users’ data.

Insecure patterns often include constructing queries by string concatenation or using ORM methods that omit tenant or user context. For example, a handler that does not scope the query by user_id or organization_id allows horizontal privilege escalation across accounts. Even when authentication is enforced, missing authorization logic at the data-access layer enables attackers to read, modify, or delete resources they should not touch. This becomes more pronounced in distributed setups where microservices call CockroachDB directly, increasing the surface for misaligned authorization boundaries.

Real-world attack patterns mirror OWASP API Top 10 A01:2023 broken object level authorization, where attackers manipulate identifiers to access sensitive records. In PCI-DSS and SOC2 contexts, this violates separation of duties and access control requirements. The issue is not CockroachDB itself but how Gin routes and handlers reference identifiers without enforcing tenant-aware scoping, leading to unauthorized data exposure and potential regulatory implications.

Remediation centers on scoping every database query to the authenticated subject and applying strict input validation. In Gin, extract the authenticated user’s ID from the context, then ensure all CockroachDB queries include this constraint. Avoid relying solely on route-level authorization; enforce it at the data-access layer.

Example: Secure handler with contextual scoping

// Assuming user identity is set in gin.Context by an auth middleware
type UserClaims struct {
    UserID   int    `json:"user_id"`
    OrgID    int    `json:"org_id"`
}

func GetUserProfile(c *gin.Context) {
    // Extract authenticated subject from context
    claims, exists := c.Get("user")
    if !exists {
        c.JSON(http.StatusUnauthorized, gin.H{"error": "unauthorized"})
        return
    }
    subject := claims.(UserClaims)

    // The requested ID from the URL
    requestedID, err := strconv.Atoi(c.Param("id"))
    if err != nil {
        c.JSON(http.StatusBadRequest, gin.H{"error": "invalid user id"})
        return
    }

    // Build a scoped query: ensure the row belongs to the authenticated user's organization
    var profile UserProfile
    row := db.QueryRow(context.Background(),
        `SELECT id, name, email, org_id FROM profiles WHERE id = $1 AND org_id = $2`,
        requestedID, subject.OrgID)
    if err := row.Scan(&profile.ID, &profile.Name, &profile.Email, &profile.OrgID); err != nil {
        if errors.Is(err, sql.ErrNoRows) {
            c.JSON(http.StatusNotFound, gin.H{"error": "resource not found or access denied"})
            return
        }
        c.JSON(http.StatusInternalServerError, gin.H{"error": "database error"})
        return
    }
    c.JSON(http.StatusOK, profile)
}

Example: Parameterized query with UUID and tenant validation

type Invoice struct {
    ID        string `json:"id"` // UUID
    OrgID     int    `json:"org_id"`
    Amount    decimal.Decimal
    CreatedBy int    `json:"created_by"`
}

func GetInvoice(c *gin.Context) {
    claims, _ := c.Get("user")
    subject := claims.(UserClaims)

    invoiceID := c.Param("invoice_id")
    // Validate UUID format before querying
    if _, err := uuid.Parse(invoiceID); err != nil {
        c.JSON(http.StatusBadRequest, gin.H{"error": "invalid invoice identifier"})
        return
    }

    var inv Invoice
    err := db.QueryRow(context.Background(),
        `SELECT id, org_id, amount, created_by FROM invoices WHERE id = $1 AND org_id = $2`,
        invoiceID, subject.OrgID).Scan(&inv.ID, &inv.OrgID, &inv.Amount, &inv.CreatedBy)
    if err != nil {
        if errors.Is(err, sql.ErrNoRows) {
            c.JSON(http.StatusNotFound, gin.H{"error": "invoice not found or access denied"})
            return
        }
        c.JSON(http.StatusInternalServerError, gin.H{"error": "database error"})
        return
    }
    // Additional check: ensure the authenticated user created or is allowed to access this invoice
    if inv.CreatedBy != subject.UserID && subject.Role != "admin" {
        c.JSON(http.StatusForbidden, gin.H{"error": "insufficient permissions"})
        return
    }
    c.JSON(http.StatusOK, inv)
}

General practices to prevent BOLA with CockroachDB in Gin

• Always scope SELECT, UPDATE, and DELETE statements with tenant or user identifiers (org_id, user_id).
• Use UUIDs or opaque identifiers instead of sequential integers to make enumeration harder, but still enforce scoping.
• Centralize data access in repository functions that automatically apply the subject’s org/user context, reducing the chance of missing checks in handlers.
• Validate input types rigorously (integers, UUID formats) to avoid injection and type confusion.
• Leverage CockroachDB’s row-level security where appropriate, but do not rely on it as the sole authorization mechanism within Gin handlers.

These steps align with OWASP API Top 10 A01, PCI-DSS access control requirements, and SOC2 logical access controls, ensuring that API endpoints remain resilient against horizontal and vertical privilege escalation when using Gin and CockroachDB.