Vulnerability management metrics in 2024: the ultimate guide

Vulnerabilities can arise in software due to existing bugs, improperly secured firewall rules, or various other reasons. If attackers succeed in exploiting these vulnerabilities, this can lead to system disruptions and serious damage to the targeted organization.

A thorough and efficient vulnerability management process is therefore key for mitigating risk. But in order to detect, remediate, and report security vulnerabilities in software and systems, you must first recognize key assets and prioritize remediation based on vulnerability severity. Moreover, you must continue to monitor the entire vulnerability risk management process, with many organizations leaning heavily on established vulnerability management metrics to track their progress and assess their security posture.

Successful vulnerability management helps your business meet compliance requirements, achieve security framework goals, and defend against breaches—while minimizing the attack surface. In this article, we’ll explore key vulnerability management metrics that help track the progress of vulnerability management programs and make the tough job of asset protection less complex.

Key vulnerability management metrics

With so many available vulnerability management metrics and insightful data available through different tools and threat intelligence frameworks, it can be hard to know what to focus on. In this article, we cover the most important metrics to help streamline your vulnerability management process.

1. Scan coverage

No vulnerability management process is complete without scan coverage, an important metric that provides a qualitative view of scan completion. Scan coverage reports reveal whether you have comprehensive scan coverage for assets and applications so that you can track and address risks as soon as they enter your system.

Scan coverage reports include the types of scanning conducted (e.g.,, agent-based), coverage analytics of all business-critical assets and applications, and the type of authentication offered (e.g., username- and password-based, or unauthenticated). Thus scan coverage helps to clarify the scope of risks.

2. Time to detection

A measure of the average time gap between the occurrence and detection of vulnerabilities across a system, time to detection helps you track data, such as the number of vulnerabilities, time of occurrence, and time of detection.

Most organizations run vulnerability-detection reports on a weekly or monthly basis, with issue trackers reducing detection time to hours, minutes, and seconds. This prevents security vulnerabilities from going unnoticed for long time spans.

3. Vulnerability age

The time a known vulnerability lives in a computing environment before a security team remediates the risk is a metric called vulnerability age. The longer the dwell time of a vulnerability in the environment, the more expensive the attack will be.

The number of attacks or potential number of attackers rises as the vulnerability age increases, indicating that the environment is prone to more attacks. The time and cost required to deal with such attacks therefore increases as well.

4. Time to remediation

This metric is a measure of the average time it takes a security team to fix identified vulnerabilities. Based on your vulnerability appetite, you should define a target time interval for planning fixes and remediating a vulnerability. Advanced security tools offer important insights and automated remediation to resolve vulnerabilities and mitigate attacks as quickly as possible.

Time to remediation provides key data, including: 

• Mean time to resolve or mitigate a vulnerability
• Number of users affected by a breach
• How fast security teams resolved an issue
• Whether the time to remediate met your organization’s defined goal 

It also helps to improve your security posture rating.

5. Patching rate

Patching is a process of addressing security flaws by adding patches or upgrading the software to the latest version. There are several patches released by software teams to fix bugs and other known vulnerabilities that may or may not be known to other public users. It is essential to apply these patches on a regular basis to stay updated and as secure as possible. 

The patching rate metric details how many patches are applied to resolve unknown or undetected vulnerabilities in the software and how much time it took security teams to apply that particular patch.

6. Average number of vulnerabilities per asset over time

It’s best practice to monitor the average number of vulnerabilities per asset over time to avoid relying on scan results that haven’t considered all your assets. This essential metric reveals the number of critical risk vulnerabilities in distinct asset groups, as well as the duration of exposure. One caveat to remember: Drops in scan results can, at times, be normal deviations.

7. Remediation results against SLAs

A service-level agreement (SLA) serves as a baseline tracker for remediation, determining when a patch is needed. Another essential vulnerability metric, SLAs are documented in the vulnerability management policy.

Companies are also bound by asset SLA compliance rules, meaning an organization needs to stick to an SLA for a particular asset. For example, immediate remediation is required for zero-day attacks, whereas remediation of critical severity findings may take around seven days.

Tracking any vulnerabilities approaching the threshold outlined in the SLA will allow you to prioritize the vulnerabilities to be remediate first. Ideally, the number of instances should be as close to zero as possible to maintain customer confidence.

Comparing the results of a fix against an SLA metric helps determine how effective a vulnerability fix is. This is done by analyzing how frequently the organization is: 

• Meeting the SLAs
• Close to breaching the SLAs
• Breaches the SLAs 

The goal is of course to try to fix a vulnerability well within the defined SLA.

8. Asset risks

When it comes to asset risk management, it’s crucial to be able to answer such questions as: 

• Which assets have the most business impact?
• How many users are granted administrative access?
• Which assets are prone to security threats?

Asset risk data helps you prioritize risk remediation so that you can invest time and resources accordingly.

9. Number of exceptions granted

Organizations often decide to exempt a specific vulnerability or group of vulnerabilities from patching or remediation. This is also known as acceptance of risk, and it’s important to track and report the number of exceptions granted so you can audit the potential impact of accepted risk.

10. Vulnerability reopen rate 

If a resolved vulnerability recurs in the same asset or a different one, this indicates a system configuration issue that needs close review. The vulnerability reopen rate metric tells about the rate at which a vulnerability reopens due to flaws in the vulnerability remediation process and in patch management.

Vulnerability & exposure management metrics and beyond

Clearly specified metrics are a critical element of vulnerability scanning reports. Without them, your organization is at risk, since this creates security and infrastructure blind spots. An effective vulnerability management system capable of detecting, assessing, reporting, and remediating vulnerabilities is therefore key.

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