Infrastructure Briefing — CISA Emergency Directive 20-01 on Windows CryptoAPI
CISA issued Emergency Directive 20-01 requiring federal civilian agencies to patch Windows systems vulnerable to CVE-2020-0601 and to inventory, monitor, and validate TLS and code-signing certificates, underscoring the operational urgency of the CryptoAPI flaw.
Executive briefing: Following disclosure of CVE-2020-0601, CISA issued Emergency Directive 20-01 on . The directive compelled federal civilian agencies to patch affected Windows systems within 10 business days, generate inventories of TLS and code-signing certificates, and monitor for anomalous validation failures to detect potential exploitation.
What changed
- Mandatory patch deployment timelines and reporting to CISA for all executive branch agencies using supported Windows versions.
- Required creation of centralized inventories of TLS certificates and code-signing certificates trusted by federal systems.
- Directed agencies to enable monitoring for invalid certificate chains and to revoke or replace impacted certificates quickly.
Why it matters
- Highlights how a cryptographic library defect can become an infrastructure-wide emergency, stressing the need for asset and certificate visibility.
- Provides a model for enterprise playbooks combining patch SLAs, telemetry checks, and reporting for high-severity vulnerabilities.
- Reinforces expectations that third-party service providers supporting federal workloads must meet rapid patch and validation requirements.
Action items for operators
- Adopt similar patch SLAs and certificate inventory practices for enterprise Windows fleets and third-party providers.
- Instrument TLS interception points and endpoints to alert on certificate validation anomalies indicative of CVE-2020-0601 exploitation.
- Coordinate with PKI teams to reissue or revoke certificates if validation anomalies are detected, and document remediation evidence for auditors.