Integrity Failures in Fiber with Cockroachdb

An Integrity Failure occurs when an application fails to enforce data correctness and trust boundaries, allowing unauthorized or inconsistent data to be written or accepted as valid. In a Fiber application using Cockroachdb as the backend, this typically surfaces through insufficient validation of request parameters before constructing SQL statements or through misuse of database transactions. Cockroachdb, as a distributed SQL database, provides strong consistency by default, but it does not protect against application-layer logic that builds unsafe queries or mishandles transaction isolation. When combined with Fiber’s fast, minimalistic routing layer, unchecked user input can be directly interpolated into SQL, leading to BOLA/IDOR-like integrity violations or property authorization failures.

For example, consider a handler that updates a user’s account balance using path parameters without verifying ownership or applying row-level checks. If the handler constructs a query by concatenating values, Cockroachdb will execute the statement as provided, which can overwrite balances for other users if the WHERE clause is incomplete or derived from untrusted data. This maps to OWASP API Top 10:2023 — API1:2023 Broken Object Level Authorization — and can be detected by middleBrick’s BOLA/IDOR and Property Authorization checks. Because Cockroachdb enforces constraints and serializable isolation, integrity failures often stem from missing application safeguards rather than database weaknesses, such as skipping optimistic checks or failing to validate version tokens before updates.

Another common scenario involves incorrect transaction usage where multiple statements are executed without proper isolation guarantees, allowing race conditions that corrupt data integrity. If a Fiber route reads a value, computes a new value, and writes it back without a conditional update or a unique constraint, concurrent requests may interleave and produce inconsistent results. middleBrick’s BFLA/Privilege Escalation and Property Authorization checks are designed to surface these classes of risk by analyzing how statements are parameterized and whether authorization is applied at the record level. Data Exposure and Input Validation checks further highlight whether integrity constraints such as uniqueness or foreign key relationships are respected during inserts or updates, ensuring that malformed payloads do not bypass business rules.

To prevent integrity failures, always validate and authorize input before constructing queries, and prefer parameterized statements to avoid accidental data corruption. In Fiber, use structured handlers that bind and validate payloads, then build Cockroachdb queries with placeholders. Below are concrete, working examples that demonstrate secure patterns for updates and conditional writes.

const { app } = require('express'); // Fiber uses a similar pattern
const { Pool } = require('pg'); // Cockroachdb wire protocol compatible
const pool = new Pool({
  connectionString: process.env.DATABASE_URL,
});

// Secure update with ownership check and conditional WHERE clause
app.put('/account/:id', async (req, res) => {
  const accountId = req.params.id;
  const { currency, amount, userId } = req.body;

  if (!currency || typeof amount !== 'number' || amount <= 0) {
    return res.status(400).send({ error: 'Invalid input' });
  }

  const client = await pool.connect();
  try {
    const query = `
      UPDATE accounts
      SET balance = balance + $1, updated_at = NOW()
      WHERE id = $2 AND user_id = $3;
    `;
    const result = await client.query(query, [amount, accountId, userId]);

    if (result.rowCount === 0) {
      return res.status(403).send({ error: 'Not authorized or record not found' });
    }

    res.send({ message: 'Balance updated successfully' });
  } catch (err) {
    console.error(err);
    res.status(500).send({ error: 'Internal error' });
  } finally {
    client.release();
  }
});

// Conditional write using Cockroachdb unique constraint and retry logic
app.post('/transfer', async (req, res) => {
  const { from_account, to_account, amount } = req.body;

  if (!from_account || !to_account || amount <= 0) {
    return res.status(400).send({ error: 'Invalid transfer request' });
  }

  const client = await pool.connect();
  let attempts = 0;
  const maxAttempts = 3;

  while (attempts < maxAttempts) {
    try {
      await client.query('BEGIN');

      const selectQuery = `SELECT balance FROM accounts WHERE id = $1 FOR UPDATE;`;
      const fromRes = await client.query(selectQuery, [from_account]);
      if (fromRes.rows.length === 0) {
        throw new Error('Source account not found');
      }
      if (fromRes.rows[0].balance < amount) {
        throw new Error('Insufficient funds');
      }

      const updateQuery = `
        UPDATE accounts
        SET balance = balance - $1
        WHERE id = $2;
      `;
      await client.query(updateQuery, [amount, from_account]);

      const insertQuery = `
        INSERT INTO ledger (from_account, to_account, amount, created_at)
        VALUES ($1, $2, $3, NOW());
      `;
      await client.query(insertQuery, [from_account, to_account, amount]);

      await client.query('COMMIT');
      return res.send({ message: 'Transfer completed' });
    } catch (err) {
      await client.query('ROLLBACK');
      if (err.message === 'Serialization failure' && attempts < maxAttempts - 1) {
        attempts++;
        continue;
      }
      console.error(err);
      return res.status(400).send({ error: err.message });
    } finally {
      client.release();
    }
  }
  res.status(409).send({ error: 'Failed after retries due to contention' });
});

These examples enforce input validation, use Cockroachdb’s FOR UPDATE to serialize access within transactions, and rely on conditional WHERE clauses that include user context to prevent unauthorized updates. By combining these patterns with middleBrick’s scans — such as the CLI tool with middlebrick scan <url> for rapid checks or the GitHub Action to fail builds when risk scores degrade — teams can continuously monitor API integrity risks. The MCP Server allows AI coding assistants to trigger scans from the IDE, helping developers catch issues early. Even with these safeguards, remember that middleBrick detects and reports findings with remediation guidance; it does not automatically fix, patch, or block execution.