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Cybersecurity Atlasby Jer Catallo

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Sensitive Data Exposure incident response playbook · Cybersecurity Atlas

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Playbook
Sensitive Data Exposure

Sensitive Data Exposure

HighData ProtectionA02:2021 – Cryptographic Failures

Sensitive data such as PII, financial records, or credentials is exposed through inadequate encryption, insecure transmission, or improper storage.

Immediate Response

1Remove or mask sensitive data from logs, error messages, and API responses immediately.
2Revoke and rotate any exposed credentials or API keys.
3Assess whether a data breach notification is required under applicable regulations (GDPR, CCPA).
4Ensure all connections between services use TLS 1.2 or higher.

Short-term Remediation

1Encrypt sensitive data at rest using AES-256 or equivalent.
2Implement field-level encryption for PII and payment data.
3Enforce TLS with HSTS across all endpoints and subdomains.
4Implement data masking in non-production environments.

Long-term Prevention

1Classify data by sensitivity and apply controls based on classification.
2Adopt a secrets management solution (e.g., HashiCorp Vault, AWS Secrets Manager).
3Conduct regular data discovery scans to find unprotected sensitive data.
4Review API response schemas to enforce data minimization principles.

Attack vectors

Data transmitted over unencrypted HTTP connections
Sensitive fields stored in plaintext or with weak encryption
Verbose error messages or debug logs exposing internal data
API responses returning more fields than required (over-fetching)

Indicators of compromise

Sensitive fields appearing in application logs or error messages
HTTP traffic carrying personal or financial data without TLS
Database backups stored without encryption in accessible locations
API responses including credit card, SSN, or password fields

Tooling

HashiCorp VaultAWS Secrets ManagerTruffleHogGitLeaksOWASP ZAP

References

owasp.org/Top10/A02_2021-Cryptographic_Failures/
cheatsheetseries.owasp.org/cheatsheets/Cryptographic_Storage_Cheat_Sheet.html