Vulnerability management is the practice of identifying, classifying, remediating, and mitigating vulnerabilities in systems, software, and networks. It is a critical part of cybersecurity as vulnerabilities are one of the main ways that attackers gain access to systems. With new vulnerabilities constantly being discovered, organizations need robust processes to find and fix vulnerabilities before they can be exploited. Here we will explore the key elements of effective vulnerability management.
Discovery
The first step in vulnerability management is discovery. Organizations need to have visibility into where vulnerabilities exist in their environment. There are several ways to do this:
- Network scans – Scan internal and external IP ranges to identify devices and known vulnerabilities.
- App scans – Scan software and applications to identify vulnerabilities in code.
- OS scans – Scan operating systems to find patch and configuration issues.
- Manual reviews – Manually review configurations and software for potential weaknesses.
- Open source intelligence – Search open source intel for new vulnerabilities in systems you use.
- Threat intelligence – Leverage threat intel feeds to learn about new vulnerabilities.
- Pen testing – Hire hackers to pen test systems and find weaknesses.
Organizations will typically use a combination of these methods on an ongoing basis to maintain visibility. Network scanning tools like Nessus and open source tools like Nmap are commonly used for automated scanning. Application security testing tools like Burp Suite are used for app scans. OS tools like Microsoft Baseline Security Analyzer can scan for missing OS patches. The key is to continuously monitor infrastructure using both active scanning and passive intelligence gathering.
Prioritization
Once vulnerabilities have been discovered, they need to be prioritized for remediation. Organizations cannot fix every vulnerability right away, so a risk-based approach is required. Prioritization considers several factors:
- Severity – How technically severe is the vulnerability and how much access/damage could it allow if exploited?
- Exploitability – How likely is this vulnerability to be exploited based on availability of exploit code and other factors?
- Impact – What is the potential business impact if this vulnerability is exploited?
- Location – Where does the vulnerability exist? Public-facing systems are higher priority.
- Compliance – Does fixing this vulnerability help meet compliance requirements?
Organizations will score and rank vulnerabilities using a rubric that weights these factors. Common scoring systems include CVSS and DREAD. Remediation efforts are focused on fixing high priority vulnerabilities first. Things like mission critical systems, internet-facing assets, and compliance mandates help prioritize as well.
Remediation
Once vulnerabilities are prioritized, the next phase is remediation. There are several potential remediation approaches:
- Patching – Install vendor patches to address known vulnerabilities in software/OS.
- Workarounds – Make configuration changes to reduce exposure, like closing ports or disabling services.
- Upgrades – Upgrade to newer software/OS versions without vulnerable code.
- Isolation – Isolate or take offline vulnerable systems that can’t be patched quickly.
- Replacement – Replace vulnerable systems that are outdated and can’t be secured.
Using the prioritized list, IT/security teams will deploy patches during maintenance windows. Workarounds provide temporary protection when patches aren’t available yet. Equipment might be isolated on separate VLANs until upgrades or replacement is feasible. The solutions depend on the specific vulnerability, affected system, and what remediation steps are possible.
Verification
After remediation, the state of vulnerabilities needs to be validated. Rescanning affected systems should be done to verify vulnerabilities have been addressed. Any remaining critical or high risk vulnerabilities need to be reexamined and prioritized again if the initial remediation was not fully effective. Security teams need to verify:
- Patches & upgrades were applied as expected
- Workarounds are in place as planned
- Isolated systems remain segmented
- No additional related vulnerabilities were introduced
Sometimes patches cause regressions or new issues. So verification is crucial after any change. Any incomplete or ineffective remediation must return to the process for re-prioritization and additional fixes until risk is reduced to an acceptable level per the organization’s policies.
Reporting
Ongoing vulnerability management requires tracking and reporting on metrics. Security leaders need visibility into the vulnerability program effectiveness. Common vulnerability management reports include:
- Current vulnerable asset inventory and severity breakdown
- Remediation times and trends
- Percentage of successful remediation
- Timeframe coverage for vulnerability scanning
- Policy compliance metrics
- Open and closed vulnerabilities per month
Reporting provides insight into where processes are working well and where improvements might be needed. Sharing reports with business leaders and application owners also helps communicate risk reduction progress.
Risk Acceptance
In rare cases, vulnerabilities may persist even after going through the discovery, prioritization, and remediation process. Examples include:
- Zero day vulnerabilities without patches
- Custom legacy systems that can’t be patched or replaced
- Commercial hardware with no vendor security support
If residual vulnerabilities remain that pose a high risk, the only option might be ongoing risk acceptance. Security owners, business leaders, and sometimes customers have to formally agree to accept the risk if it cannot be fully remediated. Strict compensating controls are implemented to minimize exposure. Accepted risks are continuously tracked and reported as part of the vulnerability management program. The goal is to minimize and eventually eliminate any accepted risks.
Emergency Response
While vulnerability management normally follows a deliberate lifecycle, new threats require an emergency response capability. When high severity vulnerabilities are disclosed publicly, organizations need to be able to quickly assess, prioritize, and remediate affected systems. This requires coordination between security teams, IT ops, vendors, and business owners. Some key aspects of emergency vulnerability response include:
- Monitoring threat intelligence for new critical vulnerabilities
- Evaluating affected assets and prioritizing response
- Patching immediately if active exploitation is occurring
- Isolating vulnerable systems that can’t be patched quickly
- Communicating with stakeholders on impact and actions
- Verifying remediation was effective across environments
Exercising the emergency plan periodically is important to keep response skills sharp. Slow response to urgent vulnerabilities can lead to costly breaches.
Program Management
The tasks described make up the technical processes of vulnerability management. But it is also important to have the management processes that oversee the program. These include:
- Asset inventory – Up-to-date list of systems in scope for scanning
- Tooling – Ensure the right tools are deployed and maintained
- Status tracking – Issue tracking for all discovered vulnerabilities
- Policy & metrics – Requirements for vulnerability identification, prioritization, and remediation
- Reporting – Regular reports for security, IT, and executives
- Roadmap – Plan for continuous improvement of capabilities
A strong program framework maximizes the impact of vulnerability management investments and process improvements. Assigning a specific manager over the vulnerability program helps maintain focus on maturing capabilities over time.
Risk Management Integration
Vulnerability management should integrate closely with other risk management functions like threat intelligence, incident response, and security monitoring. Some examples include:
- Using threat intel to prioritize vulnerabilities being targeted
- Monitoring for intrusions exploiting known vulnerabilities
- Assessing exploited vulnerabilities during incident response
- Remediating vulnerabilities as part of containment
Because vulnerabilities are a primary threat vector, vulnerability management has strong overlaps with other security risk processes. Integrating and sharing data across these programs enhances overall security posture.
Conclusion
Effective vulnerability management is not a one-time event, but a continuous cycle. The key steps include discovery, prioritization, remediation, verification, reporting, and emergency response activities. A comprehensive program requires the coordination of tools, processes, and teams. Investment in vulnerability management pays significant dividends in reducing business risk by eliminating weaknesses attackers actively exploit. Organizations that build mature vulnerability management capabilities can make dramatic improvements in their security over time.