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.
| 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 |
# 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"
# 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 = $_.LastDeploymentChangeTime.ToString('yyyy-MM-dd')
CVE = ($_.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 apt (Debian/Ubuntu)
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 yum/dnf (RHEL/CentOS)
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 []
# Ansible playbook: test_patches.yml
---
- 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 }}"
# deploy_patches.yml - Phased production rollout
---
- 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
Run a post-patch vulnerability scan to confirm patch installation:
# Trigger post-patch verification scan
curl -k -X POST "https://nessus:8834/scans/$VERIFY_SCAN_ID/launch" \
-H "X-Cookie: token=$TOKEN"
# Compare pre-patch and post-patch results
# Expecting reduction in vulnerabilities matching deployed patches
| 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 |