| name | implementing-patch-management-workflow |
| description | 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 patc |
| domain | cybersecurity |
| subdomain | vulnerability-management |
| tags | - vulnerability-management - patch-management - wsus - sccm - ansible - risk |
| version | '1.0' |
| author | mahipal |
| license | Apache-2.0 |
| nist_csf | - ID.RA-01 - ID.RA-02 - ID.IM-02 - ID.RA-06 |
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
- Discovery: Identify available patches from vendors and vulnerability scans
- Assessment: Evaluate patch applicability and risk
- Prioritization: Rank patches by severity, exploitability, and asset criticality
- Testing: Validate patches in non-production environment
- Approval: Change advisory board (CAB) review and approval
- Deployment: Phased rollout to production systems
- Verification: Confirm successful installation and no regressions
- 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)
| Ring | Environment | % of Fleet | Soak Time | Purpose |
|---|
| Ring 0 | Lab/Test | N/A | 24-48 hrs | Functional validation |
| Ring 1 | IT Early Adopters | 5% | 48-72 hrs | Real-world pilot |
| Ring 2 | Business Pilot | 15% | 5-7 days | Broader compatibility |
| Ring 3 | General Deployment | 50% | 7-14 days | Main rollout |
| Ring 4 | Mission Critical | 30% | After Ring 3 | Final deployment |
Workflow
Step 1: Configure Patch Sources
Install-WindowsFeature -Name UpdateServices -IncludeManagementTools
& "C:\Program Files\Update Services\Tools\WsusUtil.exe" postinstall CONTENT_DIR=D:\WSUS
---
- 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
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 = $_.LastDeploymentChangeTime.ToString('yyyy-MM-dd')
CVE = ($_.CveIDs -join ',')
}
} | ConvertTo-Json
"""
result = subprocess.run(
["powershell", "-Command", ps_cmd],
capture_output=True, text=True, timeout=120
)
return json.loads(result.stdout) if result.stdout.strip() else []
def get_linux_pending_patches():
"""Query package manager for available security updates."""
if platform.system() != "Linux":
return []
try:
result = subprocess.run(
["apt", "list", "--upgradable"],
capture_output=True, text=True, timeout=60
)
packages = []
for line in result.stdout.strip().split("\n")[1:]:
if line:
parts = line.split("/")
packages.append({
"package": parts[0],
"available_version": parts[1].split()[0] if len(parts) > 1 else "",
"source": "apt"
})
return packages
except FileNotFoundError:
pass
try:
result = subprocess.run(
["dnf", "updateinfo", "list", "security", "--available"],
capture_output=True, text=True, timeout=60
)
packages = []
for line in result.stdout.strip().split("\n"):
parts = line.split()
if len(parts) >= 3:
packages.append({
"advisory": parts[0],
"severity": parts[1],
"package": parts[2],
"source": "dnf"
})
return packages
except FileNotFoundError:
return []
Step 3: Patch Testing Automation
---
- name: Test Patches in Lab Environment
hosts: test_servers
become: yes
vars:
rollback_snapshot: "pre-patch-{{ ansible_date_time.date }}"
tasks:
- name: Create VM snapshot before patching
community.vmware.vmware_guest_snapshot:
hostname: "{{ vcenter_host }}"
username: "{{ vcenter_user }}"
password: "{{ vcenter_pass }}"
datacenter: "{{ datacenter }}"
name: "{{ inventory_hostname }}"
snapshot_name: "{{ rollback_snapshot }}"
state: present
delegate_to: localhost
- name: Apply security patches (RHEL/CentOS)
dnf:
name: "*"
state: latest
security: yes
update_cache: yes
when: ansible_os_family == "RedHat"
register: patch_result
- name: Apply security patches (Ubuntu/Debian)
apt:
upgrade: dist
update_cache: yes
only_upgrade: yes
when: ansible_os_family == "Debian"
register: patch_result
- name: Reboot if required
reboot:
reboot_timeout: 600
msg: "Rebooting for patch installation"
when: patch_result.changed
- name: Run post-patch validation
include_tasks: validate_services.yml
- name: Report patch results
debug:
msg: "Patching {{ 'succeeded' if patch_result.changed else 'no updates' }} on {{ inventory_hostname }}"
Step 4: Production Deployment
---
- name: Ring 1 - IT Early Adopters
hosts: ring1_hosts
serial: "25%"
max_fail_percentage: 10
become: yes
tasks:
- import_tasks: apply_patches.yml
- import_tasks: validate_services.yml
- name: Wait for soak period
pause:
hours: 48
run_once: true
- name: Ring 2 - Business Pilot
hosts: ring2_hosts
serial: "20%"
max_fail_percentage: 5
become: yes
tasks:
- import_tasks: apply_patches.yml
- import_tasks: validate_services.yml
- name: Ring 3 - General Deployment
hosts: ring3_hosts
serial: "10%"
max_fail_percentage: 3
become: yes
tasks:
- import_tasks: apply_patches.yml
- import_tasks: validate_services.yml
Step 5: Verification and Reporting
Run a post-patch vulnerability scan to confirm patch installation:
curl -k -X POST "https://nessus:8834/scans/$VERIFY_SCAN_ID/launch" \
-H "X-Cookie: token=$TOKEN"
Patch Management SLAs
| Severity | SLA (Internet-Facing) | SLA (Internal) | SLA (Air-Gapped) |
|---|
| Critical (CVSS 9+) | 48 hours | 7 days | 14 days |
| High (CVSS 7-8.9) | 7 days | 14 days | 30 days |
| Medium (CVSS 4-6.9) | 30 days | 30 days | 60 days |
| Low (CVSS 0.1-3.9) | 90 days | 90 days | 90 days |
Best Practices
- Maintain current asset inventory to ensure complete patch coverage
- Test all patches in a non-production environment before deployment
- Use phased rollouts with automatic rollback capabilities
- Coordinate patch windows with change management process
- Track patch compliance metrics and report to leadership
- Automate where possible to reduce manual effort and human error
- Maintain exception documentation for systems that cannot be patched
- Include third-party application patching (not just OS patches)
Common Pitfalls
- Patching only operating systems and ignoring third-party applications
- No rollback plan if patches cause service disruption
- Treating all patches with equal urgency (no risk-based prioritization)
- Manual patch processes that cannot scale
- No post-patch verification to confirm successful installation
- Ignoring firmware and BIOS updates
Related Skills
- prioritizing-vulnerabilities-with-cvss-scoring
- implementing-vulnerability-remediation-sla
- implementing-continuous-vulnerability-monitoring
