Implementing Patch Management Workflow

Overview

Patch management is the systematic process of identifying, testing, deploying, and verifying software updates to remediate vulnerabilities across an organization's IT infrastructure. An effective patch management workflow reduces the attack surface while minimizing operational disruption through structured testing, approval gates, and phased rollouts.

When to Use

• When deploying or configuring implementing patch management workflow capabilities in your environment
• When establishing security controls aligned to compliance requirements
• When building or improving security architecture for this domain
• When conducting security assessments that require this implementation

Prerequisites

• Vulnerability scan results identifying missing patches
• Patch management tools (WSUS, SCCM/MECM, Ansible, Intune, Jamf)
• Test environment mirroring production
• Change management process (ITIL or equivalent)
• Asset inventory with OS and application versions

Core Concepts

Patch Lifecycle Phases

1. Discovery: Identify available patches from vendors and vulnerability scans
2. Assessment: Evaluate patch applicability and risk
3. Prioritization: Rank patches by severity, exploitability, and asset criticality
4. Testing: Validate patches in non-production environment
5. Approval: Change advisory board (CAB) review and approval
6. Deployment: Phased rollout to production systems
7. Verification: Confirm successful installation and no regressions
8. Reporting: Document compliance metrics and exceptions

Patch Categories

• Security Patches: Address CVEs and security vulnerabilities
• Critical Updates: Non-security bug fixes affecting stability
• Service Packs: Cumulative update collections
• Feature Updates: New functionality (Windows feature updates, etc.)
• Firmware Updates: BIOS/UEFI, NIC, storage controller firmware
• Third-Party Patches: Adobe, Java, Chrome, Firefox, etc.

Deployment Rings (Phased Rollout)

Workflow

Step 1: Configure Patch Sources

# WSUS (Windows Server Update Services)
# Configure WSUS server to sync with Microsoft Update
# Via PowerShell on WSUS server:
Install-WindowsFeature -Name UpdateServices -IncludeManagementTools
& "C:\Program Files\Update Services\Tools\WsusUtil.exe" postinstall CONTENT_DIR=D:\WSUS

# Configure GPO for WSUS clients
# Computer Configuration > Administrative Templates > Windows Components > Windows Update
# Specify intranet Microsoft update service location: http://wsus-server:8530

# Ansible: Configure patch repositories for Linux
# roles/patch-management/tasks/configure_repos.yml
---
- name: Configure RHEL patch repository
  yum_repository:
    name: rhel-patches
    description: RHEL Security Patches
    baseurl: https://satellite.corp.local/pulp/repos/patches
    gpgcheck: yes
    gpgkey: file:///etc/pki/rpm-gpg/RPM-GPG-KEY-redhat-release
    enabled: yes

- name: Configure Ubuntu patch sources
  apt_repository:
    repo: "deb https://apt-mirror.corp.local/ubuntu {{ ansible_distribution_release }}-security main"
    state: present
  when: ansible_os_family == "Debian"

Step 2: Automated Patch Assessment

# patch_assessment.py - Correlate vulnerability scans with available patches
import subprocess
import platform
import json

def get_windows_pending_patches():
    """Query Windows Update for pending patches via PowerShell."""
    ps_cmd = """
    $Session = New-Object -ComObject Microsoft.Update.Session
    $Searcher = $Session.CreateUpdateSearcher()
    $Results = $Searcher.Search("IsInstalled=0 AND Type='Software'")
    $Results.Updates | ForEach-Object {
        [PSCustomObject]@{
            Title = $_.Title
            KB = ($_.KBArticleIDs -join ',')
            Severity = $_.MsrcSeverity
            Size = [math]::Round($_.MaxDownloadSize / 1MB, 2)
            Published = $_.LastDeploymentChangeTime.ToString('yyyy-MM-dd')

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