PCI DSS 10.3.2: Protecting Audit Logs from Unauthorized Modification
Audit logs are only valuable if they remain tamper-proof. PCI DSS 10.3.2 requires organizations to implement controls that prevent individuals—whether malicious insiders or external attackers—from modifying log files after creation. Without proper protections, modified logs destroy the audit trail and eliminate accountability.
What this means
This control mandates that audit log files be protected through technical and administrative measures to ensure they cannot be altered, deleted, or corrupted after logging occurs. This includes logs generated by cardholder data environment (CDE) systems, user activities, and security events. Protection mechanisms must make unauthorized modifications detectable or technically impossible.
How to comply
- 1.Implement centralized log management systems that aggregate logs from all CDE systems to a secure, restricted repository
- 2.Enable write-once-read-many (WORM) storage or immutable logging to prevent modification after log creation
- 3.Restrict administrative access to log files using role-based access controls (RBAC) and principle of least privilege
- 4.Implement file integrity monitoring (FIM) tools that detect unauthorized changes to audit log files
- 5.Use digital signatures or cryptographic hashing to verify log authenticity and detect tampering
- 6.Set appropriate file permissions and ownership to prevent unauthorized access or deletion
- 7.Enable system-level protections such as SELinux or Windows audit policies to restrict log file modifications
- 8.Regularly review access logs to identify and investigate suspicious modification attempts
- 9.Configure backup and archival of logs to an isolated, protected location with separate access controls
Evidence auditors look for
- Centralized SIEM or log management platform configuration showing immutable log storage
- File system permissions documentation proving restrictive access to audit log directories
- File integrity monitoring (FIM) tool configuration and alert reports
- Backup and archival procedures with evidence of isolated storage
- Digital signature or cryptographic verification implementation documentation
- Access control matrix showing RBAC for log file access
- Log retention policies defining protection periods and methods
- Monitoring reports showing detection of modification attempts
Frequently asked questions
When will FAQs be available?
The FAQ for this control is currently being prepared.
GRCWatch automatically monitors file integrity across your audit logging infrastructure, flags modification attempts in real-time, and generates PCI DSS 10.3.2 compliance evidence—eliminating manual log audits and reducing your verification burden.
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