Threat & Vulnerability Management

The optimal frequency for vulnerability scanning depends on several factors, including your organization's risk profile, regulatory requirements, rate of change in your environment, and the criticality of your assets. As a general best practice, we recommend the following scanning frequencies:

For critical assets and internet-facing systems, conduct weekly or even daily scans to quickly identify new vulnerabilities in these high-risk assets. For internal systems with moderate criticality, monthly scanning is typically sufficient to maintain an acceptable security posture. For low-criticality systems or those with minimal change, quarterly scanning may be appropriate.

Additionally, event-driven scanning should be performed after significant changes to your environment, such as new system deployments, major updates, or configuration changes. This ensures that these changes haven't introduced new vulnerabilities. It's also important to conduct scans after major vulnerability disclosures or security incidents to assess your exposure to specific threats.

Remember that vulnerability scanning is just one component of a comprehensive security program. Continuous monitoring, threat intelligence, and security testing should complement your scanning activities to provide a more complete view of your security posture.

Effective vulnerability prioritization requires a risk-based approach that goes beyond simply relying on vulnerability severity ratings like CVSS scores. We recommend a multi-factor prioritization framework that considers:

First, vulnerability characteristics including severity rating, exploitation complexity, and whether exploit code is publicly available or being actively exploited in the wild. Second, asset context such as the criticality of the affected system to your business, its exposure (internet-facing vs. internal), and the sensitivity of data it processes or stores. Third, business impact assessment of what could happen if the vulnerability were exploited, including potential financial, operational, reputational, and compliance impacts.

Fourth, threat intelligence about whether the vulnerability is being targeted by threat actors relevant to your industry or organization. Fifth, compensating controls that might reduce the risk even if the vulnerability itself isn't patched. Sixth, operational factors including remediation complexity, potential for business disruption, and resource requirements.

By combining these factors into a comprehensive risk score, you can focus your remediation efforts on the vulnerabilities that pose the greatest actual risk to your organization, rather than simply addressing all high-severity vulnerabilities first. This approach maximizes the risk reduction achieved with your available resources.

Vulnerability scanning and penetration testing are complementary security assessment approaches with different purposes, methodologies, and outcomes:

Vulnerability scanning is an automated process that identifies known vulnerabilities in systems, networks, and applications by comparing them against a database of known security issues. It's typically broad in scope, covering many systems quickly, and is conducted frequently (weekly, monthly) as part of ongoing security operations. Vulnerability scanners primarily identify the presence of vulnerabilities but don't typically exploit them to confirm their impact. The results include lists of potential vulnerabilities with severity ratings and remediation recommendations. Vulnerability scanning is relatively low-cost and can be performed by security analysts with moderate technical skills.

In contrast, penetration testing is a manual, targeted assessment conducted by skilled security professionals who simulate real-world attacks to identify and exploit vulnerabilities. It's typically narrower in scope but deeper in analysis, focusing on specific systems or applications. Penetration tests are conducted less frequently (quarterly, annually) and often in response to significant changes. Penetration testers actively exploit vulnerabilities to confirm their existence and demonstrate their potential impact, including showing how multiple lower-severity vulnerabilities might be chained together to achieve significant compromise. The results include detailed findings with proof of exploitation and strategic recommendations. Penetration testing is more resource-intensive and requires specialized expertise.

Both approaches are valuable and should be part of a comprehensive security program. Vulnerability scanning provides continuous visibility of known vulnerabilities across your environment, while penetration testing offers deeper insights into how vulnerabilities might be exploited by actual attackers.

When immediate patching isn't possible due to operational constraints, compatibility issues, or other factors, implementing compensating controls is essential to reduce the risk of vulnerability exploitation. Here's a structured approach:

First, implement network-level controls such as network segmentation to limit access to vulnerable systems, firewall rules to block exploitation attempts, and intrusion prevention systems configured to detect and block known exploitation patterns. Second, apply host-level controls including host-based firewalls, application control to prevent unauthorized code execution, and endpoint detection and response (EDR) solutions to monitor for suspicious activity.

Third, enhance monitoring and detection by implementing additional logging on vulnerable systems, creating custom detection rules for potential exploitation attempts, and increasing the frequency of log review for affected systems. Fourth, implement access restrictions by reducing the number of users with access to vulnerable systems, implementing stronger authentication requirements, and applying the principle of least privilege.

Fifth, consider application-level controls such as web application firewalls for vulnerable web applications, API gateways with security filtering for vulnerable APIs, and input validation at application boundaries. Sixth, document the vulnerability, the reasons for delayed remediation, the compensating controls implemented, and establish a timeline for permanent remediation.

Remember that compensating controls should be considered temporary measures until proper remediation can be implemented. Regular reassessment of the vulnerability's risk and the effectiveness of compensating controls is essential to ensure your security posture remains strong despite the unpatched vulnerability.

Integrating vulnerability management with DevOps processes—often referred to as DevSecOps—requires a thoughtful approach that balances security requirements with development velocity. Here's how to effectively implement this integration:

First, shift security left by integrating security testing early in the development lifecycle. This includes implementing static application security testing (SAST) during code development, software composition analysis (SCA) to identify vulnerable dependencies, and container security scanning for containerized applications. Second, automate security testing in CI/CD pipelines to ensure consistent security assessment with every build and deployment. This includes automated vulnerability scanning, security unit tests, and compliance checks.

Third, establish security gates with clear criteria for when code can proceed to the next stage of the pipeline. These gates should be risk-based, allowing minor issues to proceed while blocking critical vulnerabilities. Fourth, provide immediate feedback to developers through IDE plugins, pull request comments, and integration with development tools, making security findings actionable and easy to understand.

Fifth, implement security as code by defining security requirements, configurations, and controls as code that can be version-controlled, tested, and deployed alongside application code. Sixth, foster collaboration between security and development teams through shared responsibility models, cross-functional training, and joint planning sessions.

Seventh, measure and improve with metrics that track security findings, remediation time, and security debt, using these metrics to drive continuous improvement rather than blame. By integrating security throughout the development lifecycle and making it a shared responsibility, you can achieve both security and development velocity objectives.