Vulnerability Management Guide
Comprehensive framework for managing telecommunications security vulnerabilities from discovery through remediation
Identify assets and vulnerabilities through automated scanning, manual testing, and threat intelligence
Evaluate vulnerability severity using CVSS scoring, exploitability analysis, and business impact
Rank vulnerabilities based on risk score, asset criticality, and threat landscape
Apply patches, implement workarounds, or accept risk with documented justification
Confirm remediation effectiveness through rescanning and validation testing
Continuous surveillance for new vulnerabilities and emerging threats
Key Performance Indicators
- • Mean Time to Detect (MTTD): <24 hours for critical vulnerabilities
- • Mean Time to Remediate (MTTR): <7 days for critical, <30 days for high
- • Vulnerability Coverage: 100% of production assets scanned monthly
- • Patch Compliance: >95% of systems patched within SLA
- • False Positive Rate: <10% of identified vulnerabilities
Automated Scanning
Tools: Nessus, Qualys, OpenVAS, Rapid7 InsightVM
- • Port scanning and service detection
- • Configuration assessment
- • Missing patch identification
- • Compliance checking (PCI DSS, HIPAA)
Tools: Burp Suite, OWASP ZAP, Acunetix, Veracode
- • OWASP Top 10 vulnerability detection
- • SQL injection and XSS testing
- • Authentication and session management
- • API security assessment
Tools: Trivy, Clair, Aqua Security, Prisma Cloud
- • Container image vulnerability scanning
- • Infrastructure as Code (IaC) analysis
- • Cloud configuration assessment
- • Kubernetes security posture
Manual Testing
Quarterly external and annual internal penetration tests by certified professionals (OSCP, GPEN)
Manual security code review for critical applications and custom protocols
Security architecture assessment for new systems and major changes
Annual adversary simulation to test detection and response capabilities
Threat Intelligence
- • CVE/NVD monitoring for relevant technologies
- • Vendor security advisories and bulletins
- • CERT/CSIRT notifications
- • Security researcher disclosures
- • Dark web monitoring for leaked credentials
- • Industry-specific threat feeds (telecom ISAC)
CVSS v3.1 Scoring
Intrinsic characteristics of vulnerability
- • Attack Vector (Network, Adjacent, Local, Physical)
- • Attack Complexity (Low, High)
- • Privileges Required (None, Low, High)
- • User Interaction (None, Required)
- • Scope (Unchanged, Changed)
- • Impact (Confidentiality, Integrity, Availability)
Time-dependent factors
- • Exploit Code Maturity (Not Defined, High, Functional, POC, Unproven)
- • Remediation Level (Official Fix, Temporary Fix, Workaround, Unavailable)
- • Report Confidence (Confirmed, Reasonable, Unknown)
Customized for your environment
- • Modified Base Metrics (adjust for local conditions)
- • Confidentiality/Integrity/Availability Requirements
- • Asset criticality and business impact
Severity Classification
Immediate action required
Urgent remediation needed
Scheduled remediation
Planned remediation
Prioritization Factors
Base severity with temporal and environmental adjustments
Business impact if asset is compromised (Tier 1: Critical, Tier 2: High, Tier 3: Medium, Tier 4: Low)
Active exploitation in the wild, exploit availability, targeted attacks
Existing mitigations (WAF, IPS, network segmentation, access controls)
Risk Score Calculation
Risk Score = (CVSS × 0.4) + (Asset Criticality × 0.3) + (Threat Level × 0.2) - (Controls × 0.1)
Example: CVSS 9.0, Tier 1 Asset (10), Active Exploits (10), WAF Present (3)
Risk Score = (9.0 × 0.4) + (10 × 0.3) + (10 × 0.2) - (3 × 0.1) = 8.3 (High Priority)
Prioritization Matrix
| Risk Score | Priority | SLA | Action |
|---|---|---|---|
| 9.0-10.0 | P0 - Emergency | 24 hours | Immediate patch or isolation |
| 7.0-8.9 | P1 - Critical | 7 days | Urgent remediation |
| 5.0-6.9 | P2 - High | 30 days | Scheduled patch cycle |
| 3.0-4.9 | P3 - Medium | 90 days | Next maintenance window |
| <3.0 | P4 - Low | 180 days | Backlog or accept risk |
Preferred method for most vulnerabilities
- • Test patches in non-production first
- • Schedule maintenance windows
- • Maintain rollback procedures
- • Document all changes
- • Verify patch effectiveness
Secure configuration adjustments
- • Disable unnecessary services
- • Strengthen authentication
- • Update access controls
- • Enable security features
- • Harden system settings
When patching isn't immediately possible
- • Deploy WAF rules
- • Implement IPS signatures
- • Add network segmentation
- • Increase monitoring
- • Restrict access
Documented decision to accept risk
- • Low severity with high remediation cost
- • Legacy systems near end-of-life
- • Strong compensating controls
- • Requires executive approval
- • Annual review required
Remediation Workflow
Ticket Creation
Automatically create tickets in ITSM system with priority, SLA, and assignment
Impact Analysis
Assess remediation impact on business operations and dependencies
Change Request
Submit change request with rollback plan and testing procedures
Implementation
Execute remediation during approved maintenance window
Verification
Rescan to confirm vulnerability is resolved and no new issues introduced
Documentation
Update asset inventory, close tickets, and document lessons learned
Monitoring Activities
- • Automated vulnerability scanning on schedule
- • Real-time threat intelligence feeds
- • Configuration drift detection
- • New asset discovery
- • Vendor security bulletin monitoring
- • Patch availability tracking
- • Deployment status reporting
- • Compliance verification
- • Vulnerability trends and aging
- • MTTR by severity level
- • SLA compliance rates
- • Risk score distribution
Reporting Framework
- • Overall risk posture and trends
- • Critical/high vulnerability counts
- • SLA compliance metrics
- • Top 10 risks and remediation status
- • Budget and resource requirements
- • New vulnerabilities discovered
- • Remediation progress by team
- • Overdue vulnerabilities
- • Scan coverage and exceptions
- • False positive analysis
- • Regulatory compliance status
- • Audit findings and remediation
- • Policy exceptions and approvals
- • Third-party risk assessments
- • Certification maintenance
Success Metrics
2.3
vulnerabilities per asset (target: <3.0)
4.2d
for critical vulnerabilities (target: <7d)
97%
systems patched within SLA (target: >95%)
73%
reduction in high/critical vulns (target: >70%)