Application vulnerability remediation is a critical process that every organization should implement to identify and fix security weaknesses in their software. By defining a standard remediation process and automating it where possible, teams can address vulnerabilities efficiently and consistently. Effective vulnerability management requires collaboration between security and development teams throughout the software development lifecycle.

Where did this come from?

This control comes from the CSA Cloud Controls Matrix v4.0.10 - 2023-09-26 which can be downloaded at https://cloudsecurityalliance.org/artifacts/cloud-controls-matrix-v4. The CCM provides a comprehensive set of cloud security controls mapped to various industry standards. For more information on application security and vulnerability management, check out the AWS Web Application Firewall (WAF) documentation.

Who should care?

This control is relevant for:

• Application security engineers responsible for identifying and triaging vulnerabilities
• Developers who need to understand secure coding practices and how to remediate issues
• DevOps teams that manage the software development pipeline and deployment processes
• IT leadership and executives accountable for the overall security posture of the organization

What is the risk?

Unpatched application vulnerabilities expose the organization to:

• Data breaches resulting in unauthorized access to sensitive information
• Malware infections that compromise system integrity
• Denial-of-service attacks that impact application availability
• Reputational damage and loss of customer trust
• Regulatory fines and legal liability

Implementing a vulnerability remediation program can significantly reduce these risks by ensuring a consistent process exists to identify, prioritize, and remediate security weaknesses in a timely manner. The extent to which risks are reduced depends on the maturity of the program and how quickly vulnerabilities are patched.

What's the care factor?

Application vulnerabilities should be a top priority for any organization that develops or uses software. Exploitable weaknesses provide an easy entry point for attackers to gain unauthorized access to systems and data. The consequences can be severe - data breaches, system outages, financial losses, and damaged reputation. Security debt tends to accrue over time as unpatched vulnerabilities pile up.

While in an ideal world all vulnerabilities would be fixed immediately, in reality organizations must prioritize based on risk. Vulnerabilities that are easier to exploit, more widely known, or impact critical assets should be remediated first. At a minimum, all critical and high severity vulnerabilities should have a target remediation deadline.

When is it relevant?

A vulnerability remediation process is relevant for:

• All public-facing web applications
• Critical internal business applications that process sensitive data
• Applications that are part of the software supply chain
• Legacy applications with known security debt
• Applications developed by third-parties

It may be less relevant for:

• Isolated applications not accessible from the internet
• Test or pre-production environments
• Appliances with automated patch management
• Applications scheduled for decommissioning

What are the trade offs?

Implementing application vulnerability remediation has the following costs:

• Increased workload for development and security teams to triage, prioritize, and fix vulnerabilities
• Potential for business disruption if production systems need to be patched quickly
• Opportunity cost of diverting resources away from feature development
• Licensing and implementation costs for vulnerability scanners and automation tools

On the other hand, proactively managing vulnerabilities can save money in the long run by:

• Avoiding fines and legal fees associated with data breaches
• Preventing loss of revenue due to system outages or customer churn
• Reducing incident response time and effort
• Lowering cyber insurance premiums

How to make it happen?

To implement application vulnerability remediation:

1. Establish a vulnerability management policy that defines the processes, roles, and responsibilities for vulnerability handling.
2. Integrate security testing into the SDLC, including static code analysis and dynamic vulnerability scans.
3. Aggregate vulnerability findings into a centralized system of record such as a defect tracker or GRC platform.
4. Prioritize vulnerabilities based on severity, exploitability, and asset criticality. Use the Common Vulnerability Scoring System (CVSS) as a guide.
5. Apply automated remediation where possible, for example using Infrastructure-as-Code to patch systems or dependency management tools to update vulnerable libraries.
6. Set service level agreements (SLAs) for vulnerability patching based on the assigned priority. Critical - 7 days, High - 30 days, Medium - 90 days is a common starting point.
7. Define an exception process for vulnerabilities that cannot be fixed by the SLA due to business reasons. Require sign-off from application owners and security leadership.
8. Provide secure coding training to developers and consider implementing bug bounty programs to identify gaps.
9. Regularly report on vulnerability trends and metrics such as time-to-remediate and average risk score.

What are some gotchas?

Be mindful of the following when implementing vulnerability management:

• Teams need adequate permissions to run scans and access issues - for AWS this may include IAM policies such as EC2:DescribeInstances and IAM:GetAccessKeyLastUsed.
• False positives can undermine the credibility of the program - tune scanners and train developers to identify irrelevant results.
• Scans must be scheduled with consideration for business impact. Avoid running intensive scans on production systems during peak hours.
• Third-party and open source components introduce visibility challenges. Use software composition analysis (SCA) to identify issues in the supply chain.

Refer to the AWS documentation for further details on permissions and vulnerability scanning tools: https://docs.aws.amazon.com/inspector/latest/userguide/inspector_introduction.html

What are the alternatives?

Runtime Application Self-Protection (RASP) tools provide an alternative approach to identifying and blocking vulnerabilities in real-time. RASP works by instrumenting application binaries to detect and prevent malicious behavior. This can reduce patching overhead but has limitations - it cannot fix the underlying flaw and may negatively impact performance.

Managed application security providers are another option to augment in-house teams. Many offer integrated scanning, prioritization, and remediation workflows. However, this comes at a cost and requires careful vetting to ensure vendors have adequate security controls.

Explore further

For more information on vulnerability management, refer to:

• OWASP Top 10 Vulnerabilities
• NIST Cybersecurity Framework v1.1 PR.IP-12 sub-category
• AWS Vulnerability Management Blog
• CIS Control 16 Application Software Security
• CIS Control 7 Continuous Vulnerability Management

?