In this project, I 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)
- 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- Remediation Round 1: Outdated Wireshark Removal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
- Remediation Round 5: CertPaddingCheck
- Remediation Round 6: Require SMB Signing
- Remediation Round 7: Block ICMP Timestamp
- First Cycle Remediation Effort Summary
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
- WinVerifyTrust
- SMBSigningNotRequired
- Block ICMP Timestamp (Requests & Replies)
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.
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
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
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
The server team used a PowerShell script to mitigate the WinVerifyTrust Signature Validation CVE-2013-3900 vulnerability by enabling the EnableCertPaddingCheck registry setting. A follow-up scan verified successful remediation.
PowerShell: WinVerifyTrust Signature Vadlidation Remediation
Scan 6 - WinVerifyTrust Remediation
The server team used a PowerShell script to mitigate the "SMB Signing not required" vulnerability by enabling the following: "Microsoft network client: Digitally sign communications (always)" and "Microsoft network server: Digitally sign communications (always)". A follow-up scan verified successful remediation.
PowerShell: SMB Signing Not Required Remediation
Scan 7 - SMB Signing Not Required Remediation
The server team used a PowerShell script to create a firewall rule to block ICMP Timestamp Requests(Type 13) and Replies(Type 14). A follow-up scan verified successful remediation.
PowerShell: Block ICMP Timestamp Requests And Replies
Scan 8 - Block ICMP Timestamp Remediation
The remediation process reduced total vulnerabilities by 93%, from 29 to 2.
- Criticals: 100% resolved, from 2 to 0
- Highs: 100% resolved, from 9 to 0
- Mediums: 88% resolved, from 17 to 2
- Lows: 100%, from 1 to 0
In an actual production environment, asset criticality would further guide future remediation efforts.
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.