PIISecurityBest PracticesCompliance

Preventing Data Leaks: Control Sensitive Information at the Source

Thomas NelsonMay 30, 20268 min read

Title: Stop Data Leaks at the Source

During production, enabling debug mode can unintentionally expose sensitive JSON data. If a masking system only activates after 15 minutes, that's too late. An unmasked SSN in archived logs highlights just how insufficient post-processing solutions can be.

Why This Problem Persists

  • Default logging often reveals sensitive data.
  • Replicating logs increases risk.
  • Verbose libraries let data slip through.
  • Redaction rules may overlook new entries.
  • High-pressure environments can lead to sloppy practices.

Why Common Fixes Don’t Work

  • Regex scrubbing is unreliable.
  • "We don’t log PII" policies aren’t always enforced.
  • Cleanups can't recover all copies.
  • Limiting access doesn’t prevent initial leaks.
  • Short retention doesn't stop immediate exposure.

Solution: Stop Data at the Source

Key Strategies

  • Implement structured logging.
  • Use a deny-by-default policy.
  • Integrate sensitivity-aware APIs.
  • Employ secure formatters and redact at boundaries.
  • Filter data before logging.
  • Create protocols for safe debugging.

Getting Started (30-60 Days)

  • Pinpoint where data is emitted.
  • Standardize your logging practices.
  • Set up log management middleware.
  • Apply in-process attribute filters.
  • Make sure log agents skip sensitive fields.
  • Default to controlled, structured logs.
  • Build controls into the SDLC.
  • Address past leaks and update credentials.

Developer Practices

  • Only log non-sensitive data.
  • Use hashed references securely.
  • Gather sanitized logs for debugging.

Expectations and Tradeoffs

  • Initial schema enforcement takes time.
  • Deny-by-default might feel limiting but is essential.
  • Keep filtering costs low.
  • Carefully manage hashing and rotation.

Success Indicators

  • Sensitive data isn’t logged.
  • Configuration complexity decreases.
  • Better incident details without the risk.
  • New systems integrate smoothly.

Conclusion

Reactive masking isn’t enough. Start by controlling data from the point of creation using structured and careful methods to avoid exposure.

NEXTChoose your next proof

Review a Scanner finding or logging requirement against your existing controls. If a recurring gap remains, scope one CerbiShield workload, policy, evaluation window, and evidence review.

One initial workload/Customer-hosted in Azure/Existing destinations remain
Preventing Data Leaks: Control Sensitive Information at the Source | Cerbi Blog