What is Vulnerability Management

Vulnerability management extends beyond your perimeter. When vendors process your data or connect to your systems, their unpatched vulnerabilities become your risk exposure. A SQL injection flaw in your payment processor's API or an unpatched RCE vulnerability in your cloud provider's infrastructure can devastate your security posture regardless of your internal controls.

Effective third-party vulnerability management requires visibility into vendor patching practices, remediation timelines, and compensating controls. You need evidence of regular vulnerability assessments, documented remediation procedures, and metrics showing mean time to remediation (MTTR) for critical findings. Without this visibility, you're accepting unknown risk that regulatory frameworks explicitly require you to manage.

Core Components of Vulnerability Management

A mature vulnerability management program operates on four pillars:

1. Asset Discovery and Inventory You can't protect what you don't know exists. This includes:

• Network-accessible systems and services
• Web applications and APIs
• Cloud workloads and containers
• Third-party components and dependencies

2. Vulnerability Identification Regular scanning using multiple detection methods:

• Network vulnerability scanners (Nessus, Qualys, Rapid7)
• Web application scanners (Burp Suite, OWASP ZAP)
• Static and dynamic code analysis
• Container image scanning
• Software composition analysis (SCA) for dependencies

3. Risk-Based Prioritization Not all vulnerabilities warrant immediate action. Prioritization factors include:

• CVSS base score and temporal metrics
• Asset criticality and data classification
• Exploit availability (EPSS scores, KEV catalog)
• Business context and compensating controls

4. Remediation and Verification Tracked remediation with defined SLAs:

• Critical (CVSS 9.0+): 7-14 days
• High (CVSS 7.0-8.9): 30 days
• Medium (CVSS 4.0-6.9): 90 days
• Low (CVSS 0.1-3.9): Best effort or risk acceptance

Regulatory Requirements for Vulnerability Management

SOC 2 Type II

Trust Services Criteria CC7.1 specifically requires organizations to "identify and manage system vulnerabilities." Auditors expect:

• Documented vulnerability management procedures
• Evidence of regular scanning (monthly minimum)
• Remediation tracking with closure verification
• Metrics showing remediation performance

ISO 27001:2022

Control A.12.6.1 mandates "timely information about technical vulnerabilities." Requirements include:

• Formal vulnerability management policy
• Regular vulnerability assessments
• Risk treatment decisions for each finding
• Management review of vulnerability trends

PCI DSS v4.0

Requirement 11.3 explicitly requires:

• Quarterly internal vulnerability scans
• Annual penetration testing
• Rescanning until high-risk vulnerabilities are resolved
• Authenticated scanning for accurate results

GDPR Article 32

While not prescriptive, GDPR requires "appropriate technical measures" including:

• Regular testing and evaluation of security measures
• Ability to restore availability after incidents
• Documentation of security decisions

Third-Party Vulnerability Management Challenges

Managing vendor vulnerabilities introduces unique complexities:

Limited Visibility You rarely have direct access to scan vendor infrastructure. Instead, you rely on:

• Attestation reports (SOC 2, ISO certificates)
• Penetration test summaries
• Vulnerability disclosure statements
• Security ratings services

Contractual Constraints Your ability to mandate remediation depends on:

• Right-to-audit clauses
• SLA definitions for security issues
• Liability and indemnification terms
• Termination rights for unresolved risks

Scale and Prioritization With hundreds of vendors, you must:

• Risk-tier vendors based on data access and criticality
• Define different assessment depths per tier
• Automate evidence collection where possible
• Focus manual review on critical vendors

Practical Implementation Framework

Tier 1: Critical Vendors

• Quarterly vulnerability assessment reports required
• 30-day remediation SLA for critical findings
• Annual penetration test with executive summary
• Monthly security metrics dashboard

Tier 2: Important Vendors

• Semi-annual vulnerability summaries
• 60-day remediation SLA for critical findings
• Vulnerability management policy review
• Annual security questionnaire

Tier 3: Standard Vendors

• Annual attestation of vulnerability management
• Best-effort remediation commitments
• Security ratings monitoring
• Incident notification requirements

Common Vulnerability Management Failures

1. Scanning Without Remediation Organizations often scan religiously but fail to track remediation. Vulnerability scanners become expensive paperweights without closed-loop tracking.

2. Missing Context Raw CVSS scores don't reflect real risk. A CVSS 10.0 vulnerability on an isolated test system poses less risk than a CVSS 7.0 flaw in your payment gateway.

3. Incomplete Asset Coverage Traditional scanners miss:

• Cloud-native workloads
• Containerized applications
• Serverless functions
• API endpoints
• Mobile applications

4. Ignoring Third-Party Libraries Software composition analysis reveals that 70-the majority of modern applications consist of third-party components. Log4Shell demonstrated how dependency vulnerabilities can devastate entire ecosystems.

Industry-Specific Considerations

Financial Services: Regulatory guidance from OCC, FDIC, and Federal Reserve explicitly requires vendor vulnerability management. FFIEC examination procedures check for evidence of ongoing assessments.

Healthcare: HIPAA Security Rule §164.308(a)(8) requires periodic technical vulnerability assessments. OCR audits examine both internal and business associate vulnerability management.

Technology: Cloud service providers must demonstrate vulnerability management through SOC 2 Type II reports, ISO 27017 certification, and CSA STAR attestation.

Frequently Asked Questions

How often should we require vulnerability assessments from vendors?

Critical vendors handling sensitive data should provide quarterly assessments. Important vendors can report semi-annually, while standard vendors may provide annual attestations.

What's the difference between vulnerability scanning and penetration testing?

Vulnerability scanning uses automated tools to identify known weaknesses. Penetration testing involves skilled testers attempting to exploit vulnerabilities to demonstrate real-world impact.

Should we accept vendor self-assessments for vulnerability management?

Self-assessments are acceptable only for low-risk vendors. Critical and important vendors should provide independent assessment reports or allow direct audits.

How do we handle vendors who refuse to remediate vulnerabilities?

Document the risk, implement compensating controls where possible, and consider contract termination if the risk exceeds your tolerance. Maintain evidence of all remediation requests.

What vulnerability metrics should we track for vendors?

Track mean time to detect (MTTD), mean time to remediate (MTTR) by severity, percentage of overdue vulnerabilities, and number of critical vulnerabilities open beyond SLA.

Can we rely on security ratings services instead of vulnerability reports?

Security ratings provide useful indicators but shouldn't replace direct evidence for critical vendors. Use ratings for continuous monitoring between formal assessments.

How do we verify that vendors actually remediated reported vulnerabilities?

Require evidence of remediation such as retest reports, patch deployment logs, or configuration changes. For critical findings, consider requiring independent validation.