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Source: ocean/docs/posthog-security-audit-report.md | ✏️ Edit on GitHub

PostHog CDP Security and Integration Audit Report

Date: 2025-07-31
Auditor: System Security Scan
Scope: PostHog CDP integration, Edge Functions, Database access, and Feature Flags system

Executive Summary​

This audit identified several security vulnerabilities and integration issues in the PostHog CDP setup. The most critical findings include exposed API keys in documentation and .env files, missing Row Level Security (RLS) policies on database views, and hardcoded passwords in migration files.

Findings by Severity​

🔴 Critical (Immediate Action Required)​

1. Exposed API Keys in Repository​

  • Location: .env file, multiple documentation files
  • Details:
    • PostHog API key exposed: phc_hqVEnjLBIdcwVAmYEkTWTHxBaEQVOQ7Mmi31fiUofIp
    • PostHog Personal API key exposed: phx_PouzmcqYyxFoAgdAtHgTQQTTWFwktPKQEhkaFLSzMmMQmUI
  • Risk: Anyone with access to the repository can use these keys to track events or access analytics data
  • Recommendation:
    1. Immediately rotate all exposed keys in PostHog dashboard
    2. Remove .env from repository
    3. Add .env to .gitignore
    4. Use environment variables in CI/CD and deployment environments only

2. Hardcoded Default Password in Migration​

  • Location: /supabase/migrations/20250131000002_posthog_readonly_user.sql:8
  • Details: CREATE USER posthog_readonly WITH PASSWORD 'CHANGE_ME_IN_SUPABASE_DASHBOARD'
  • Risk: If not changed, provides database access to anyone who knows the default
  • Recommendation:
    1. Verify the password has been changed in production
    2. Update migration to not include a default password
    3. Document the password setup process separately

🟠 High (Address Within 24-48 Hours)​

3. Missing Row Level Security on PostHog Views​

  • Location: Database views posthog_users, posthog_user_profiles, posthog_organization_metrics
  • Details: Views are created without RLS policies, potentially exposing all user data
  • Risk: The posthog_readonly user can access all data across all organizations
  • Recommendation:
    1. Add RLS policies to restrict data access
    2. Consider creating filtered views per organization
    3. Implement view-level security checks

4. Webhook Secret Verification Issues​

  • Location: /supabase/functions/auth-hook/index.ts, /supabase/functions/database-hook/index.ts
  • Details: Webhook secret is optional - functions accept requests without verification if not set
  • Risk: Unauthorized webhook calls could be made if secret is not configured
  • Recommendation:
    1. Make webhook secret mandatory
    2. Fail closed - reject requests without proper verification
    3. Add rate limiting to webhook endpoints

5. Exposed Sensitive User Data in Views​

  • Location: posthog_users view
  • Details: Exposes email addresses, IP addresses, and metadata without filtering
  • Risk: PII exposure to analytics system
  • Recommendation:
    1. Hash or pseudonymize email addresses
    2. Remove or mask IP addresses
    3. Filter sensitive metadata fields

🟡 Medium (Address Within 1 Week)​

6. Missing Authentication in Feature Flag Evaluation​

  • Location: /supabase/functions/feature-flags/index.ts
  • Details: While auth token is verified, there's no validation that the user has permission to evaluate flags for a given organization
  • Risk: Users could potentially evaluate flags for organizations they don't belong to
  • Recommendation:
    1. Add organization membership validation
    2. Implement flag-level access controls
    3. Add audit logging for flag evaluations

7. Insecure Feature Flag Storage​

  • Location: Feature flag evaluations stored in database
  • Details: Flag evaluation history includes potentially sensitive context data
  • Risk: Historical data could reveal business logic or user behavior patterns
  • Recommendation:
    1. Implement data retention policies
    2. Encrypt sensitive context data
    3. Add access controls to evaluation history

8. Missing Rate Limiting​

  • Location: All Edge Functions
  • Details: No rate limiting implemented on PostHog tracking calls
  • Risk: Could lead to quota exhaustion or cost overruns
  • Recommendation:
    1. Implement per-user rate limits
    2. Add circuit breakers for PostHog API calls
    3. Monitor and alert on high usage

🟢 Low (Address Within 1 Month)​

9. Incomplete Error Handling​

  • Location: PostHog Edge Functions
  • Details: Errors are logged but not properly categorized or monitored
  • Risk: Silent failures could lead to data loss
  • Recommendation:
    1. Implement structured error logging
    2. Add error metrics and alerting
    3. Create fallback mechanisms for tracking

10. Missing Field Validation​

  • Location: PostHog tracking implementations
  • Details: No validation on event properties before sending to PostHog
  • Risk: Invalid data could corrupt analytics
  • Recommendation:
    1. Add Zod schemas for event validation
    2. Sanitize user input before tracking
    3. Implement property whitelisting

Integration Gaps​

Missing Integration Points​

  1. User Deletion Workflow: No process to remove user data from PostHog when deleted from database
  2. Data Sync Validation: No mechanism to verify PostHog data matches database state
  3. Feature Flag Sync: Database flags not synchronized with PostHog feature flags
  4. Billing Events: Missing tracking for failed payment attempts and dunning processes

Missing Data Fields​

  1. User Profiles: Missing company size, use case, and referral source
  2. Organization Data: Missing MRR, churn risk score, and health metrics
  3. Feature Usage: Missing detailed feature interaction timestamps
  4. Performance Metrics: Missing API response times and error rates

Security Best Practices Not Followed​

  1. Principle of Least Privilege: posthog_readonly user has SELECT on all tables
  2. Defense in Depth: Single point of failure if PostHog API key is compromised
  3. Data Minimization: Collecting more data than necessary for analytics
  4. Secure by Default: Optional security features instead of mandatory

Recommendations Priority Matrix​

Immediate Actions (Today)​

  1. Rotate all exposed API keys
  2. Remove .env from repository
  3. Change posthog_readonly database password
  4. Add webhook secret verification

Short Term (This Week)​

  1. Implement RLS policies on views
  2. Add organization-level access controls
  3. Implement rate limiting
  4. Add data validation

Medium Term (This Month)​

  1. Implement comprehensive audit logging
  2. Add data retention policies
  3. Create security monitoring dashboards
  4. Implement automated security testing

Long Term (This Quarter)​

  1. Migrate to PostHog's SDK for feature flags
  2. Implement end-to-end encryption for sensitive data
  3. Create disaster recovery procedures
  4. Conduct penetration testing

Conclusion​

The PostHog CDP integration has several critical security vulnerabilities that need immediate attention. The exposed API keys and missing access controls pose significant risks to data security and privacy. Implementing the recommended fixes will significantly improve the security posture of the integration.

Appendix: Security Checklist​

  • All API keys rotated and secured
  • .env removed from repository
  • Database passwords changed from defaults
  • RLS policies implemented on all views
  • Webhook signatures verified on all endpoints
  • Rate limiting implemented
  • Data validation added to all tracking calls
  • Audit logging enabled
  • Security monitoring configured
  • Documentation updated with security best practices