Restrict inbound traffic to system components in the CDE
Description
Inbound traffic to the cardholder data environment must be restricted to only necessary connections.
⚠️ Risk Impact
Unrestricted inbound access exposes payment processing systems to external attacks.
🔧 Remediation
Configure firewall rules to allow only required traffic. EchelonGraph detects overly permissive firewall rules.
💀 Real-World Attack Scenario
A payment processor had overly permissive firewall rules allowing any internal IP to reach the CDE. An attacker who compromised a marketing server used it as a jump box to access the CDE network, installed a memory scraper on the POS processing server, and captured 2.3M card numbers over 6 months.
💰 Cost of Non-Compliance
Target 2013: $292M total cost from CDE firewall failures. PCI DSS Req 1.3.1 violation: $5K-$100K/month in fines + immediate Level 1 re-assessment. Card brand fines: $50K-$500K per incident.
📋 Audit Questions
- 1.Show the CDE network diagram with all ingress/egress points.
- 2.What firewall rules allow traffic into the CDE?
- 3.Are only required ports and protocols allowed?
- 4.How frequently are CDE firewall rules reviewed?
🎯 MITRE ATT&CK Mapping
⚡ Common Pitfalls
- ⛔Allowing all internal traffic to the CDE (segmentation failure)
- ⛔Not documenting business justification for each CDE firewall rule
- ⛔Using broad port ranges instead of specific service ports
📈 Business Value
Proper CDE network segmentation reduces PCI DSS audit scope by 80%+ and prevents the most common payment data breach vector — lateral movement from compromised internal systems.
⏱️ Effort Estimate
8-16 hours for CDE segmentation review and firewall rule audit
EchelonGraph scans firewall rules for CDE boundary violations
🔗 Cross-Framework References
Automate PCI DSS 1.3.1 compliance
EchelonGraph continuously monitors this control across all your cloud accounts.
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