In this project, I was able to simulate the implementation of a comprehensive vulnerability management program, from inception to completion.
Inception State: the organization has no existing policy or vulnerability management practices in place.
Completion State: a formal policy is enacted, stakeholder buy-in is secured, and a full cycle of organization-wide vulnerability remediation is successfully completed.
- Tenable (enterprise vulnerability management platform)
- Azure Virtual Machines (Nessus scan engine + scan targets)
- PowerShell & BASH (remediation scripts)
- Step 1) Vulnerability Management Policy Draft Creation
- Mock Meeting: Policy Buy-In (Stakeholders)
- Policy Finalization and Senior Leadership Sign-Off
- Mock Meeting: Initial Scan Permission (Server Team)
- Initial Scan of Server Team Assets
- Vulnerability Assessment and Prioritization
- Distributing Remediations to Remediation Teams
- Mock Meeting: Post-Initial Discovery Scan (Server Team)
- Mock CAB Meeting: Implementing Remediations
- Remediation Round 1: Outdated Wireshark Removal
- Remediation Round 2: Insecure Protocols & Ciphers
- Remediation Round 3: Guest Account Group Membership
- Remediation Round 4: Windows OS Updates
- First Cycle Remediation Effort Summary
- STIG Remediation: Windows 11 Hardening (DISA STIG v2r7)
This phase focuses on drafting a Vulnerability Management Policy as a starting point for stakeholder engagement. The initial draft outlines scope, responsibilities, and remediation timelines, and may be adjusted based on feedback from relevant departments to ensure practical implementation before final approval by upper management.
Draft Policy
In this phase, a meeting with the server team introduces the draft Vulnerability Management Policy and assesses their capability to meet remediation timelines. Feedback leads to adjustments, like extending the critical remediation window from 48 hours to one week, ensuring collaborative implementation.
After gathering feedback from the server team, the policy is revised, addressing aggressive remediation timelines. With final approval from upper management, the policy now guides the program, ensuring compliance and reference for pushback resolution.
Finalized Policy
The team collaborates with the server team to initiate scheduled credential scans. A compromise is reached to scan a single server first, monitoring resource impact, and using just-in-time Active Directory credentials for secure, controlled access.
In this phase, an insecure Windows Server is provisioned to simulate the server team's environment. After creating vulnerabilities, an authenticated scan is performed, and the results are exported for future remediation steps.
We assessed vulnerabilities and established a remediation prioritization strategy based on ease of remediation and impact. The following priorities were set:
- Third Party Software Removal (Wireshark)
- Windows OS Secure Configuration (Protocols & Ciphers)
- Windows OS Secure Configuration (Guest Account Group Membership)
- Windows OS Updates
The server team received remediation scripts and scan reports to address key vulnerabilities. This streamlined their efforts and prepared them for a follow-up review.
The server team reviewed vulnerability scan results, identifying outdated software, insecure accounts, and deprecated protocols. The remediation packages were prepared for submission to the Change Control Board (CAB).
The Change Control Board (CAB) reviewed and approved the plan to remove insecure protocols and cipher suites. The plan included a rollback script and a tiered deployment approach.
The server team used a PowerShell script to remove outdated Wireshark. A follow-up scan confirmed successful remediation.
Wireshark Removal Script
CVEs Addressed:
| CVE ID | Description | CVSS Score |
|---|---|---|
| CVE-2023-0666 | Wireshark RTPS Dissector Crash (DoS via crafted packet) | 7.5 High |
| CVE-2023-2879 | Wireshark GDSDB Dissector Infinite Loop (DoS) | 7.5 High |
| CVE-2023-4511 | Wireshark BT SDP Dissector Infinite Loop (DoS) | 7.5 High |
Scan 2 - Third Party Software Removal
The server team used PowerShell scripts to remediate insecure protocols and cipher suites. A follow-up scan verified successful remediation, and the results were saved for reference.
PowerShell: Insecure Protocols Remediation
PowerShell: Insecure Ciphers Remediation
CVEs Addressed:
| CVE ID | Description | CVSS Score |
|---|---|---|
| CVE-2014-3566 (POODLE) | SSLv3 CBC padding oracle allows plaintext recovery | 3.4 Low |
| CVE-2015-4000 (Logjam) | Weak DHE key exchange enables MITM downgrade to 512-bit export | 3.7 Low |
| CVE-2016-0800 (DROWN) | SSLv2 support allows decryption of TLS sessions | 5.9 Medium |
Scan 3 - Ciphersuites and Protocols
The server team removed the guest account from the administrator group. A new scan confirmed remediation, and the results were exported for comparison.
PowerShell: Guest Account Group Membership Remediation
CVEs Addressed:
| CVE ID | Description | CVSS Score |
|---|---|---|
| CVE-2021-36934 (HiveNightmare) | Windows SAM database readable by non-admins; over-privileged accounts amplify exposure | 7.8 High |
| CVE-2021-34484 | Windows User Profile Service elevation of privilege via improper access controls | 7.0 High |
Scan 4 - Guest Account Group Removal
Windows updates were re-enabled and applied until the system was fully up to date. A final scan verified the changes.
CVEs Addressed:
| CVE ID | Description | CVSS Score |
|---|---|---|
| CVE-2024-49112 | Windows LDAP Remote Code Execution via specially crafted LDAP call | 9.8 Critical |
| CVE-2024-49138 | Windows CLFS Driver elevation of privilege (kernel-mode exploit) | 7.8 High |
| CVE-2024-43451 | Windows NTLM Hash Disclosure via minimal user interaction | 6.5 Medium |
The remediation process reduced total vulnerabilities by 80%, from 30 to 6. Critical vulnerabilities were resolved by the second scan (100%), and high vulnerabilities dropped by 90%. Mediums were reduced by 76%. In an actual production environment, asset criticality would further guide future remediation efforts.
To demonstrate baseline hardening capabilities beyond vulnerability management, a Windows 11 virtual machine was assessed against the DISA Security Technical Implementation Guide (STIG) for Windows 11, Version 2 Release 7 (V2R7). The initial assessment revealed 152 failed findings spanning audit policy, account policy, system services, and registry configuration.
Automated remediation was performed using custom PowerShell scripts targeting the highest-priority Category I (CAT I) and Category II (CAT II) findings:
| STIG ID | Control Description |
|---|---|
| WN11-00-000145 | Disabled legacy SMBv1 protocol |
| WN11-AC-000005 | Enforced account lockout policy (5 invalid attempts) |
| WN11-EP-000001 | Enabled Windows Defender Credential Guard |
| WN11-AU-000040 | Configured audit policies for logon/logoff events |
| WN11-SO-000090 | Disabled anonymous enumeration of SAM accounts and shares |
| WN11-CC-000185 | Removed AutoPlay from all drives |
| WN11-SO-000230 | Enforced FIPS-compliant cryptographic algorithms |
| WN11-CC-000155 | Disabled WDigest authentication (prevents plaintext credential caching) |
Results: Automated script execution reduced failed findings from 152 to 17 — an 89% reduction in non-compliant controls.
| Assessment Stage | Failed Findings | Pass Rate |
|---|---|---|
| Pre-Hardening (Baseline) | 152 | ~40% |
| Post-Script Execution | 17 | ~93% |
The remaining 17 findings required manual remediation or had operational dependencies (e.g., smart card enforcement in a standalone lab environment) that were outside the scope of automated scripting.
After completing the initial remediation cycle, the vulnerability management program transitions into Maintenance Mode. This phase ensures that vulnerabilities continue to be managed proactively, keeping systems secure over time. Regular scans, continuous monitoring, and timely remediation are crucial components of this phase. (See Finalized Policy for scanning and remediation cadence requirements.)
Key activities in Maintenance Mode include:
- Scheduled Vulnerability Scans: Perform regular scans (e.g., weekly or monthly) to detect new vulnerabilities as systems evolve.
- Patch Management: Continuously apply security patches and updates, ensuring no critical vulnerabilities remain unpatched.
- Remediation Follow-ups: Address newly identified vulnerabilities promptly, prioritizing based on risk and impact.
- Policy Review and Updates: Periodically review the Vulnerability Management Policy to ensure it aligns with the latest security best practices and organizational needs.
- Audit and Compliance: Conduct internal audits to ensure compliance with the vulnerability management policy and external regulations.
- Ongoing Communication with Stakeholders: Maintain open communication with teams responsible for remediation, ensuring efficient coordination.
By maintaining an active vulnerability management process, organizations can stay ahead of emerging threats and ensure long-term security resilience.