Patch Management Best Practices

Master the art of keeping systems secure through effective patch management strategies

What is Patch Management?

Patch Management is the systematic process of identifying, testing, deploying, and verifying software updates that fix vulnerabilities, bugs, and improve functionality across your IT infrastructure.

Effective patch management is one of the most critical security controls. The majority of successful cyberattacks exploit known vulnerabilities that have available patches - meaning they were preventable with proper patch management.

According to industry research, organizations that patch critical vulnerabilities within 24 hours reduce breach risk by up to 90%. Yet many breaches occur because patches were available but not applied.

What is Patch Management?

Patch Management is the systematic process of identifying, testing, deploying, and verifying software updates that fix vulnerabilities, bugs, and improve functionality across your IT infrastructure.

Effective patch management is one of the most critical security controls. The majority of successful cyberattacks exploit known vulnerabilities that have available patches — meaning they were preventable with proper patch management.

Organizations that patch critical vulnerabilities within 24 hours reduce breach risk dramatically, yet many incidents occur because patches were available but not applied.

Patch Prioritization Timeline

Critical Patches

24-48 Hours
  • CVSS 9.0-10.0 vulnerabilities
  • Actively exploited vulnerabilities (check CISA KEV)
  • Internet-facing systems and critical infrastructure
  • Zero-day vulnerabilities with available patches

High Priority Patches

7 Days
  • CVSS 7.0-8.9 vulnerabilities
  • Vulnerabilities with public exploits
  • Important business systems

Medium Priority Patches

30 Days
  • CVSS 4.0-6.9 vulnerabilities
  • Standard business systems

Low Priority Patches

Next Maintenance Window
  • CVSS 0.1-3.9 vulnerabilities
  • Feature updates and non-security improvements

The Patch Management Process

1

Inventory & Discovery

Maintain an accurate inventory of all assets, software, and versions

  • • Automated asset discovery and tracking
  • • CMDB or asset management database
  • • Software inventory with version tracking
  • • Identify end-of-life or unsupported systems
2

Patch Identification

Monitor vendor security bulletins and vulnerability databases

  • • Subscribe to vendor security advisories
  • • Monitor CVE databases and CISA alerts
  • • Use vulnerability scanners to identify missing patches
  • • Track patch release announcements
3

Assessment & Prioritization

Evaluate patches and determine deployment priority

  • • Review vulnerability severity (CVSS scores)
  • • Check for active exploitation
  • • Assess business impact of patch and vulnerability
  • • Identify affected systems and their criticality
4

Testing

Test patches in a controlled environment before production deployment

  • • Deploy to test or staging environment first
  • • Verify application functionality
  • • Check for compatibility issues
  • • Document rollback procedures
  • • For critical patches, balance testing time with risk
5

Deployment

Roll out patches in a controlled, phased approach

  • • Schedule during maintenance windows (except critical patches)
  • • Deploy in waves: pilot group then broader deployment
  • • Coordinate with business stakeholders
  • • Use automation tools for consistency
  • • Keep a rollback plan ready
6

Verification

Confirm patches were successfully applied and systems are functioning

  • • Verify patch installation status
  • • Re-scan to confirm vulnerability is resolved
  • • Monitor system performance and stability
  • • Check for any adverse effects
  • • Update asset inventory and documentation

Emergency Patching Procedures

When to Bypass Normal Procedures

Some situations require immediate action with abbreviated testing:

  • Active exploitation: Attackers are actively targeting the vulnerability
  • Wormable vulnerabilities: Can spread automatically without user interaction
  • Critical internet-facing systems: Exposed and easily accessible to attackers
  • CISA KEV catalog additions: Government-confirmed exploitation in the wild

Emergency Patching Process

  1. 1. Immediate Assessment: Confirm the vulnerability affects your systems
  2. 2. Risk Acceptance: Get executive approval to bypass normal testing
  3. 3. Minimal Testing: Quickly validate the patch does not brick systems
  4. 4. Staged Deployment: Small pilot group first, then rapid rollout
  5. 5. Intensive Monitoring: Watch closely for issues during and after deployment
  6. 6. Communication: Keep stakeholders informed throughout

Compensating Controls

When patches are not immediately available or cannot be deployed right away, implement these temporary mitigations:

Network Controls

  • • Firewall rules to block exploit attempts
  • • Network segmentation to isolate vulnerable systems
  • • IPS or IDS signatures to detect exploitation
  • • VPN requirements for access

Application Controls

  • • WAF rules to filter malicious requests
  • • Disable vulnerable features or components
  • • Increase authentication requirements
  • • Input validation and sanitization

Monitoring & Detection

  • • Enhanced logging and alerting
  • • Threat hunting for indicators of compromise
  • • Behavioral analysis for anomalies
  • • SIEM rules for exploitation attempts

Administrative Controls

  • • Restrict access to vulnerable systems
  • • Require additional approval workflows
  • • Increase security awareness training
  • • Document exceptions and review regularly

Common Patching Challenges & Solutions

Challenge: Legacy Systems That Cannot Be Patched

Solution: Isolate in a separate network segment, implement strict access controls, use virtual patching with IPS or WAF, and plan migration to supported systems

Challenge: 24/7 Production Systems With No Downtime Window

Solution: Implement high-availability architecture with rolling updates, use blue-green or canary deployments, and schedule emergency maintenance for critical patches

Challenge: Patches Breaking Applications

Solution: Maintain a robust test environment, implement automated testing, document dependencies, keep rollback procedures ready, and engage application owners early

Challenge: Too Many Patches to Manage

Solution: Automate patch deployment where possible, focus on risk-based prioritization, consolidate vendors or products, and implement continuous patching versus scheduled windows

Challenge: Limited IT Resources

Solution: Leverage automation and orchestration tools, use managed patch services, prioritize critical and high-risk systems, and implement auto-update where appropriate

Patch Management Tools

Windows

  • • WSUS
  • • Microsoft SCCM
  • • Windows Update for Business
  • • Intune

Linux

  • • Ansible
  • • Puppet
  • • Chef
  • • SaltStack

Cross-Platform

  • • Ivanti
  • • ManageEngine
  • • SolarWinds
  • • PDQ Deploy

Stay informed about the latest vulnerabilities requiring patches

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