1. Identify CVEs in Your Systems

The first step in fixing vulnerabilities is identifying which CVEs affect your systems. Start by scanning all components of your infrastructure, including servers, endpoints, applications, and networks. Use automated vulnerability scanners to streamline the process.

• Network Scanners: Tools like Nessus, OpenVAS, and Qualys help identify open ports, outdated software, and misconfigurations.
• Application Scanners: OWASP ZAP and Burp Suite focus on web applications, detecting SQL injections, XSS, and other vulnerabilities.
• Patch Management Tools: Solutions like WSUS, SCCM, or third-party tools identify missing patches in operating systems and applications.

Conduct scans regularly, particularly after deploying new software, updates, or changes to infrastructure. Create an asset inventory to track software versions and correlate them with known vulnerabilities.

2. Analyze and Prioritize Based on CVSS Scores

Not all vulnerabilities pose the same level of risk. The Common Vulnerability Scoring System (CVSS) helps prioritize which CVEs to fix first. Each CVE receives a numerical score between 0 and 10 based on its impact, exploitability, and environmental context.

• Critical (9.0-10.0): Immediate remediation required as these vulnerabilities are actively exploited or expose critical systems.
• High (7.0-8.9): Address these vulnerabilities within a defined timeline to prevent exploitation.
• Medium (4.0-6.9): Evaluate risks and schedule patches based on organizational priorities.
• Low (0.1-3.9): Low impact, often requires further review or deferral.

Use risk-based prioritization, considering business impact, asset importance, and exploit availability. Tools like NVD, CVE Details, and Mitre help provide detailed insights into each CVE.

3. Apply Security Patches

Once CVEs are prioritized, applying patches is critical to eliminate vulnerabilities. Follow a structured approach to ensure minimal disruption and effectiveness:

• Testing: Test patches in a staging environment to verify compatibility and stability.
• Deployment: Roll out patches in phases, starting with critical systems and high-priority CVEs.
• Automation: Use tools like Ansible, SCCM, or WSUS to automate patch deployment across systems.
• Rollback Plans: Always prepare rollback mechanisms in case patches cause disruptions.

Vendor advisories often release specific remediation instructions. Be sure to subscribe to their security bulletins to receive updates promptly.

4. Monitor and Validate

Fixing vulnerabilities does not end with patching. Continuous monitoring is essential to validate that systems are secure and no new vulnerabilities emerge. Implement proactive measures:

• Vulnerability Scanning: Perform follow-up scans to verify that patches were successfully applied.
• SIEM Solutions: Use tools like Splunk or ELK Stack to monitor logs and detect potential threats.
• Incident Response Plans: Ensure quick remediation for newly discovered vulnerabilities by automating workflows.

Regular audits and penetration testing help validate security controls and identify overlooked vulnerabilities. Maintain documentation for compliance and continuous improvement.