Formula Injection in Cockroachdb

Formula injection in Cockroachdb environments typically occurs when application code constructs SQL queries using untrusted input without proper sanitization. Unlike traditional SQL injection where malicious SQL syntax is injected, formula injection specifically targets the query construction logic that Cockroachdb uses to optimize and execute queries.

The most common manifestation involves Cockroachdb's query planner being manipulated through specially crafted input that affects how the database interprets join conditions, filter predicates, or ORDER BY clauses. For example, when building dynamic queries for filtering data based on user input, an attacker might supply values that cause the query planner to generate suboptimal execution plans or expose unintended data.

Consider this vulnerable pattern in Go code using the Cockroachdb driver:

func getUsersByStatus(status string) (*sql.Rows, error) {
    query := fmt.Sprintf("SELECT * FROM users WHERE status = '%s'", status)
    return db.Query(query)
}

An attacker could supply: active' OR 1=1-- which transforms the query into:

SELECT * FROM users WHERE status = 'active' OR 1=1--'

The double-dash comments out the trailing quote, causing the WHERE clause to always evaluate to true and return all user records.

Cockroachdb's specific implementation of the PostgreSQL wire protocol makes it particularly vulnerable to certain injection patterns. The database's handling of dollar-quoted strings ($$...$$) and its support for multiple dollar sign variations can be exploited when input isn't properly sanitized. Additionally, Cockroachdb's JSONB operators and functions provide additional injection vectors if user input is incorporated into JSON path expressions without validation.

Another Cockroachdb-specific scenario involves the INTERLEAVE keyword used in table creation for interleaved indexing. If application logic dynamically constructs table creation statements or ALTER TABLE commands based on user input, an attacker could inject INTERLEAVE clauses to manipulate index structures or cause denial of service through excessive index creation.

Detecting formula injection in Cockroachdb requires a multi-layered approach that combines static analysis, runtime monitoring, and specialized scanning tools. The database's distributed architecture and SQL dialect create unique detection challenges that differ from traditional relational databases.

Static code analysis should focus on identifying dangerous string concatenation patterns in database query construction. Tools like sqlparse can help identify potentially vulnerable query building patterns in Go, Python, or Node.js codebases that interact with Cockroachdb. Look specifically for:

• fmt.Sprintf() or similar formatting functions used with SQL queries
• Direct string concatenation with user input
• Dynamic query construction in ORM configurations
• Raw SQL execution without parameterization

Runtime detection in Cockroachdb can leverage the database's built-in audit logging and slow query monitoring. Enable the crdb_internal.statement_statistics table to track query patterns and identify suspicious execution times that might indicate injection attempts. Monitor for:

SELECT * FROM crdb_internal.statement_statistics WHERE query LIKE '% OR %' OR query LIKE '%--%';

Cockroachdb's EXPLAIN ANALYZE output can reveal when query plans deviate from expected patterns, potentially indicating injection attempts that manipulate the query optimizer. Unusual join patterns or unexpected table scans in the execution plan should trigger alerts.

For comprehensive detection, middleBrick's API security scanner specifically tests Cockroachdb endpoints by sending crafted payloads that target common injection patterns. The scanner identifies vulnerable query construction by observing database responses to controlled inputs. middleBrick tests 12 security categories including authentication bypasses and input validation issues that could enable formula injection.

middleBrick's approach includes testing Cockroachdb-specific features like JSONB operators, INTERLEAVE syntax, and the database's handling of special characters in identifiers. The scanner provides a security risk score (A–F) with findings that include the exact location and nature of vulnerabilities, along with remediation guidance specific to Cockroachdb's implementation.

Remediating formula injection in Cockroachdb applications requires a defense-in-depth approach that combines secure coding practices, database configuration hardening, and runtime protection. The most critical remediation is eliminating dynamic SQL construction entirely in favor of parameterized queries.

Instead of the vulnerable pattern:

query := fmt.Sprintf("SELECT * FROM users WHERE status = '%s'", status)
rows, err := db.Query(query)

Use parameterized queries:

query := "SELECT * FROM users WHERE status = $1"
rows, err := db.Query(query, status)

The $1 placeholder ensures that Cockroachdb treats the input as data rather than executable SQL, regardless of its content. This pattern applies to all query types including INSERT, UPDATE, and DELETE statements.

For complex dynamic queries where the number of parameters varies, use Cockroachdb's support for array parameters:

query := "SELECT * FROM users WHERE status = ANY($1)"
statuses := []string{"active", "pending"}
rows, err := db.Query(query, pq.Array(statuses))

Implement strict input validation at the application layer before queries reach the database. Use Cockroachdb's native type system to enforce data constraints:

CREATE TABLE users (
    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
    email STRING UNIQUE NOT NULL CHECK (email LIKE '%_@__%.__%'),
    status STRING NOT NULL CHECK (status IN ('active', 'inactive', 'pending'))
);

The CHECK constraints prevent invalid data from being inserted, providing an additional layer of protection against injection attempts that try to bypass application validation.

Configure Cockroachdb's role-based access control (RBAC) to limit database permissions to the minimum required for each application component. Create specific database roles with read-only access for reporting queries and separate roles for data modification operations.

CREATE ROLE api_reader;
GRANT SELECT ON users TO api_reader;
CREATE ROLE api_writer;
GRANT INSERT, UPDATE, DELETE ON users TO api_writer;

Enable Cockroachdb's audit logging to track all database operations and set up alerts for unusual query patterns. Use the crdb_internal.node_statement_statistics view to monitor query execution patterns across the cluster.

For applications that must use dynamic SQL construction, implement a query builder layer that validates and sanitizes all input before query generation. Cockroachdb's SQL parser can be used to validate query syntax before execution:

func validateQuery(query string) error {
    _, err := sqlparser.Parse(query)
    return err
}

This validation catches malformed queries and suspicious patterns before they reach the database engine.