Email Injection in Cockroachdb

Email injection in Cockroachdb environments typically occurs when user input containing newline characters is improperly handled in email-related operations. This vulnerability allows attackers to inject additional email headers or modify the content of emails sent through applications using Cockroachdb as a backend.

The most common manifestation involves SQL queries that construct email content or headers using string concatenation. Consider a typical scenario where an application stores email templates in a Cockroachdb table and dynamically inserts user data:

INSERT INTO email_templates (template_id, subject, body) VALUES (1, 'Welcome!', 'Hello {{user.name}},

Welcome to our service!');

An attacker could exploit this by submitting a name containing newline characters and additional headers:

John Doe
CC: victim@example.com
Subject: Phishing Email

When the template engine processes this input, the resulting email might include unauthorized headers and altered content. This is particularly dangerous in Cockroachdb applications because the database often stores configuration data, user preferences, and notification templates that can be manipulated.

Cockroachdb's JSONB and ARRAY data types can also be vectors for email injection when used to store email configurations. A common pattern involves storing email recipient lists:

INSERT INTO notification_settings (user_id, email_preferences) VALUES (123, '{"recipients": ["user@example.com"]}');

If the application later constructs email headers from this JSON data without proper validation, an attacker who can modify their notification settings could inject additional recipients or headers.

Stored procedures in Cockroachdb that handle email operations present another attack surface. Consider a procedure that sends notifications:

CREATE PROCEDURE send_notification(IN recipient TEXT, IN subject TEXT, IN body TEXT) AS $$ BEGIN -- Email sending logic here END; $$ LANGUAGE plpgsql;

If any of these parameters contain malicious newline sequences, the email generation process could be compromised. The procedural nature of these operations makes input validation critical.

Cockroachdb's distributed architecture can amplify email injection impacts. Since data is replicated across nodes, a single injection vulnerability could affect email operations across the entire cluster. Additionally, Cockroachdb's support for multi-region deployments means that injected emails could be sent from various geographic locations, complicating detection and response.

Application code that interfaces with Cockroachdb often uses ORMs or query builders that may not properly escape email-related content. For example, using string interpolation in Go with a Cockroachdb driver:

query := fmt.Sprintf("SELECT template_body FROM email_templates WHERE template_id = %d", templateID)

While this example doesn't directly show email injection, similar patterns in email construction code can lead to vulnerabilities. The key is that Cockroachdb applications must treat email headers and bodies as special content requiring strict validation, not just generic text fields.

Detecting email injection vulnerabilities in Cockroachdb requires a multi-layered approach that examines both the database schema and application code patterns. middleBrick's scanning capabilities are particularly effective for this purpose, as they can identify risky query patterns without requiring access to source code.

The first detection layer involves schema analysis. middleBrick scans Cockroachdb schemas for tables and columns that store email-related content, looking for patterns like:

SHOW COLUMNS FROM information_schema.columns WHERE column_name LIKE '%email%' OR column_name LIKE '%subject%' OR column_name LIKE '%body%';

Tables identified through this analysis are then examined for injection vulnerabilities. middleBrick tests for common injection patterns by submitting payloads containing newline characters and observing how the database handles them.

For Cockroachdb's JSONB columns, middleBrick performs specialized analysis to detect email injection risks:

SELECT column_name, data_type FROM information_schema.columns WHERE data_type = 'JSONB' AND (table_name LIKE '%email%' OR table_name LIKE '%notification%' OR table_name LIKE '%template%');

The scanner then attempts to inject malicious JSON structures that could affect email generation logic. This includes testing for array injection where additional recipients could be added:

{"recipients": ["victim@example.com", "attacker@example.com"]}

middleBrick's LLM security features are particularly relevant for Cockroachdb applications that use AI-powered email generation. The scanner tests for system prompt leakage and prompt injection in any AI services integrated with the Cockroachdb backend. This is crucial because AI-generated emails might incorporate user data from the database without proper sanitization.

Stored procedure analysis is another critical detection component. middleBrick examines Cockroachdb's pg_catalog to identify procedures that handle email operations:

SELECT proname, prosrc FROM pg_catalog.pg_proc WHERE prosrc ILIKE '%email%' OR prosrc ILIKE '%notification%';

For each identified procedure, the scanner tests parameter handling to ensure that newline characters and other injection vectors are properly managed.

Application-level detection involves analyzing the query patterns that interact with Cockroachdb. middleBrick's black-box scanning tests unauthenticated endpoints to identify how email-related data flows through the system. This includes testing for:

• Header injection through form fields that populate email subjects
• Body injection through user comments or feedback stored in the database
• Template injection through dynamic content generation
• Configuration injection through email settings storage

The scanner also checks for Cockroachdb-specific features that could be exploited, such as computed columns that generate email content or views that combine multiple data sources for email generation.

middleBrick provides a comprehensive report showing the exact queries and payloads that triggered email injection vulnerabilities, along with severity ratings based on the potential impact. The scanner maps findings to OWASP API Top 10 categories, specifically targeting A04:2021 - Unrestricted Resource Consumption and A07:2021 - Identification and Authentication Failures where email injection often leads to unauthorized access or data exfiltration.

Remediating email injection vulnerabilities in Cockroachdb applications requires a defense-in-depth approach that combines database-level protections, application-level validation, and secure coding practices. The following strategies are specifically tailored for Cockroachdb environments.

The foundation of remediation is strict input validation using Cockroachdb's built-in validation features. For columns that store email content, implement CHECK constraints that reject newline characters:

ALTER TABLE email_templates ADD CONSTRAINT no_newlines CHECK (subject !~ '
|
' AND body !~ '
|
');

This prevents injection at the database level, ensuring that even if application code has vulnerabilities, the database won't accept malicious input. For JSONB columns storing email configurations, use similar constraints:

ALTER TABLE notification_settings ADD CONSTRAINT valid_email_config CHECK (jsonb_array_length(email_preferences->'recipients') < 100);

Application-level validation should use Cockroachdb's prepared statements exclusively for email-related operations. This prevents SQL injection that could lead to email injection:

PREPARE email_query AS SELECT template_body FROM email_templates WHERE template_id = $1; EXECUTE email_query(123);

For Go applications using the Cockroachdb driver, always use parameterized queries:

stmt, err := db.Prepare("SELECT template_body FROM email_templates WHERE template_id = $1") if err != nil { return err } rows, err := stmt.Query(templateID) if err != nil { return err }

Sanitization functions should be implemented at the application layer before data reaches Cockroachdb. Create utility functions that strip or encode newline characters in email content:

func sanitizeEmailContent(input string) string { return strings.ReplaceAll(input, "
", " ") } // Or use more sophisticated encoding

For Cockroachdb's procedural language, create validation functions:

CREATE OR REPLACE FUNCTION validate_email_input(text) RETURNS BOOLEAN AS $$ BEGIN RETURN $1 !~ '
|
'; END; $$ LANGUAGE plpgsql;

Stored procedures that handle email operations should include validation checks:

CREATE PROCEDURE send_notification(IN recipient TEXT, IN subject TEXT, IN body TEXT) AS $$ DECLARE valid_input BOOLEAN; BEGIN valid_input := validate_email_input(subject) AND validate_email_input(body); IF NOT valid_input THEN RAISE EXCEPTION 'Invalid email input detected'; END IF; -- Email sending logic here END; $$ LANGUAGE plpgsql;

For applications using Cockroachdb's changefeeds to trigger email notifications, implement filtering to prevent injection through change data:

CREATE CHANGEFEED INTO 'kafka://...' WITH confluent_schema_registry = '...' , format = 'json', confluent_key = 'raw', confluent_value = 'schema_only' AS SELECT * FROM orders WHERE status = 'completed' AND validate_email_input(customer_notes);

Regular security testing should be integrated into your development workflow. Use middleBrick's CLI tool to scan your Cockroachdb-backed APIs:

npx middlebrick scan https://api.yourservice.com --output json --severity high

Configure GitHub Actions to run these scans automatically:

name: API Security Scan on: [push] jobs: scan: runs-on: ubuntu-latest steps: - uses: actions/checkout@v2 - name: Run middleBrick scan run: | npx middlebrick scan $API_URL --output json --fail-on-severity high

Monitoring is essential for ongoing security. Set up Cockroachdb's built-in auditing to track email-related operations:

ALTER TABLE email_templates EXPERIMENTAL_AUDIT SET READ WRITE;

This creates audit logs that can help detect injection attempts. Combine this with middleBrick's continuous monitoring in the Pro tier to get alerts when new vulnerabilities are detected.

Finally, establish a security policy that defines acceptable email content and enforces it through both technical controls and code review processes. This includes guidelines for handling user-generated content that might be included in emails, such as comments, feedback, or dynamic data from Cockroachdb queries.