External PCI Validation
In cybersecurity, External PCI Validation refers to the comprehensive and independent process of verifying an organization's adherence to the Payment Card Industry Data Security Standard (PCI DSS) from an "outside-in" perspective. This validation explicitly assesses the effectiveness of security controls visible or accessible from the internet or other public networks.
The core purpose of External PCI Validation is to determine if an attacker, operating from outside the organization's perimeter, could compromise the Cardholder Data Environment (CDE) or sensitive payment card data by exploiting weaknesses in publicly exposed assets. It contrasts with internal audits that evaluate controls from within the organization's network.
Key aspects of External PCI Validation include:
Attack Surface Assessment: Identifying all internet-facing components that could be potential entry points into the network, such as public IP addresses, domains, subdomains, web applications, APIs, cloud services, and remote access points.
Vulnerability Scanning (External): Conducting scans on the external network perimeter and public-facing applications to detect known security vulnerabilities, misconfigurations, and outdated software that could be exploited. This often involves using Approved Scanning Vendors (ASVs) for quarterly scans, as mandated by PCI DSS.
External Penetration Testing: Performing simulated attacks from an external vantage point to identify exploitable vulnerabilities that automated scans might miss. This includes attempting to bypass security controls, gain unauthorized access to systems, or exfiltrate sensitive data.
Web Application Security Testing: Rigorously testing public-facing web applications for common vulnerabilities like SQL injection, cross-site scripting (XSS), insecure direct object references, and weak session management, which are frequent targets for attackers seeking payment data.
Network Security Control Review: Verifying the effectiveness of external firewalls, intrusion prevention systems, and other network access controls in segmenting the CDE and restricting unauthorized traffic.
Sensitive Data Exposure Checks: Actively looking for any inadvertent exposure of sensitive information (e.g., plain-text credentials, API keys, or even cardholder data) in public code repositories, cloud storage, dark web forums, or publicly accessible files.
Third-Party External Posture: Evaluating the external security posture of third-party service providers who store, process, or transmit CHD on behalf of the organization, as their security is directly tied to the organization's compliance.
DNS and Email Security Verification: Confirming proper configuration of DNS security extensions (DNSSEC) and email security protocols (like SPF, DKIM, DMARC) to prevent domain spoofing, phishing, and other attacks that could lead to CDE compromise.
External PCI Validation provides an objective and real-world assessment of an organization's perimeter defenses against threats to payment card data. It's a critical component of a robust PCI DSS compliance program, helping organizations proactively identify and remediate weaknesses before malicious actors exploit them.
ThreatNG, an all-in-one external attack surface management, digital risk protection, and security ratings solution, can significantly help organizations with External PCI Validation by providing a continuous, attacker-eye view of their digital footprint related to cardholder data.
External Discovery & Continuous Monitoring
ThreatNG performs purely external, unauthenticated discovery, identifying assets and risks from an attacker's perspective without needing connectors. This is critical for External PCI Validation because it uncovers unknown or rogue assets that might be storing, processing, or transmitting cardholder data (CHD) and thus fall within PCI DSS scope. ThreatNG monitors an organization's external attack surface, digital risk, and security ratings. This ongoing monitoring ensures that new exposures or changes to existing assets that could impact PCI DSS compliance are immediately identified, providing real-time visibility into the organization's external security posture.
Examples of ThreatNG's help:
Identifying Undocumented Assets: ThreatNG can discover "Applications Identified" and login pages that the organization may not have formally tracked. If these applications handle CHD, their discovery is vital for External PCI Validation, ensuring they are inventoried and secured according to PCI DSS Requirement 1.4.2. ThreatNG's continuous discovery helps ensure all such interfaces are known, tracked, and subject to proper security governance.
Detecting New Exposures from Misconfigurations: Through continuous monitoring, ThreatNG can identify newly exposed services on non-standard ports, as indicated by "Custom Port Scan" results or "Default Port Scan" findings. If these ports are open to services that could lead to the CDE, ThreatNG's immediate identification allows for proactive security measures, preventing potential entry points for attackers. This directly relates to PCI DSS Requirement 1.1.6 (restricting traffic to necessary ports).
ThreatNG performs a variety of external assessments that directly contribute to External PCI Validation by highlighting potential attack vectors and data leakage points from an external perspective:
Web Application Hijack Susceptibility: ThreatNG analyzes the external attack surface of web applications, including domain intelligence, to identify potential entry points for attackers. This directly supports PCI DSS Requirement 6.4.3, which mandates protections for public-facing web applications against attacks.
Example: If ThreatNG identifies "Subdomains Missing Content Security Policy", it signals a vulnerability that attackers could use for cross-site scripting (XSS) or other injection attacks. This finding, often discovered during vulnerability scans or penetration tests (PCI DSS 11.3.1) , indicates a gap in application security controls (PCI DSS 6.4.2), which ThreatNG's external assessment validates.
Subdomain Takeover Susceptibility: ThreatNG evaluates a website's susceptibility to subdomain takeover by analyzing subdomains, DNS records, and SSL certificate statuses. A successful subdomain takeover can lead to defacement, phishing, or malware distribution, all of which are critical breach scenarios that PCI DSS aims to prevent.
Example: ThreatNG detecting a "Subdomain Takeover" vulnerability means an unmanaged asset could be hijacked. This directly impacts PCI DSS 1.4.2 (maintaining inventory) and 11.3.1 (pen testing external interfaces) , as hijacked subdomains can be used for phishing or script injection on trusted domains, falling under 6.4.3 (protecting public-facing web apps).
Cyber Risk Exposure: This assessment considers parameters like certificates, subdomain headers, vulnerabilities, and sensitive ports. It also factors in "Code Secret Exposure," which involves discovering code repositories and investigating their contents for sensitive data. These are all critical components for understanding external exposure that could lead to CDE compromise.
Example: ThreatNG detecting "Invalid Certificates" on a public-facing web application highlights a weakness in cryptographic protection (PCI DSS 4.2.1) and a direct violation of 4.2.2 (valid certificates). ThreatNG's external assessment validates this gap in secure configuration (PCI DSS 2.2.6).
Example: The discovery of "Private IPs Found" in public DNS reveals internal network architecture. ThreatNG identified this information, which can bypass network segmentation (PCI DSS 1.1.1), making it a critical component of External PCI Validation as it exposes systems crucial for protecting cardholder data.
Cloud and SaaS Exposure: ThreatNG evaluates sanctioned and unsanctioned cloud services and Software-as-a-Service (SaaS) solutions, including identifying "Open Exposed Cloud Buckets" of AWS, Microsoft Azure, and Google Cloud Platform. This is crucial for External PCI Validation, as cloud environments are frequently used for storing or processing CHD, and unknown or misconfigured instances pose a significant risk.
Example: ThreatNG discovering "Files in Open Cloud Buckets" directly highlights a data exposure risk that could include CHD. This finding immediately validates a critical, potentially overlooked, component that must be addressed per PCI DSS 3.1.1 (retain cardholder data only if required).
Mobile App Exposure: ThreatNG evaluates how exposed an organization's mobile apps are through discovery in marketplaces and by analyzing their content for "Access Credentials," "Security Credentials," and "Platform Specific Id” Mobile applications can directly interact with or expose CHD.
Example: ThreatNG identifying "Mobile Application Exposure Sensitive Information Found" means sensitive data, such as APIs or basic auth credentials, are present within mobile applications. This finding is critical for External PCI Validation as it points to potential violations of PCI DSS requirements related to sensitive authentication data storage (PCI DSS 3.2).
Breach & Ransomware Susceptibility: This assessment considers exposed sensitive ports, private IPs, known vulnerabilities, compromised credentials, and ransomware events/gang activity. These findings directly contribute to External PCI Validation by identifying specific points of weakness and active threats that attackers could target to compromise the CDE.
Example: ThreatNG identifies "Ransomware events" associated with the organization and provides intelligence about active data availability and integrity threats. This directly contributes to External PCI Validation, prompting immediate activation of incident response procedures (PCI DSS 12.10.5).
Web Application Firewalls (WAFs) Missing: ThreatNG explicitly identifies when "Web Application Firewalls (WAFs) Missing" occurs on subdomains. The absence of a WAF means public-facing web applications are more exposed to vulnerabilities (PCI DSS 6.6), and intrusion detection/prevention systems may be inadequate (PCI DSS 11.4). ThreatNG's ability to externally validate this absence is key to PCI compliance.
Example: ThreatNG reporting "Web Application Firewalls (WAFs) Missing" on a subdomain directly indicates a critical gap in protecting public-facing web applications (PCI DSS 6.6) and a weakness in intrusion prevention capabilities (PCI DSS 11.4). This external validation immediately flags a non-compliant state from an attacker's perspective.
ThreatNG provides comprehensive reports, including "Inventory" reports, "Security Ratings", and "External GRC Assessment Mappings (eg, PCI DSS)". These reports are invaluable for External PCI Validation:
The Inventory report directly supports the ongoing cataloging of assets that are part of or linked to the CDE's external attack surface.
External GRC Assessment Mappings allow organizations to see how discovered external risks, like "Subdomains Missing Content Security Policy," align with specific PCI DSS requirements. This helps prioritize remediation efforts for exposures that most directly impact PCI DSS compliance and security, informing the management of External PCI Validation.
The "Security Ratings" provide a balanced view of an organization's security posture, including "Positive Security Indicators" like WAF presence. These serve as objective evidence of adequate controls from an external attacker's perspective.
ThreatNG's core capability is "Continuous Monitoring of external attack surface, digital risk, and security ratings of all organizations". This is fundamental to External PCI Validation, as the external attack surface is dynamic. New assets can be deployed, configurations can change, or sensitive data can be inadvertently exposed. Continuous monitoring ensures that the external PCI validation remains current, providing real-time awareness of new components that fall into the CDE scope or pose a risk to it.
ThreatNG's investigation modules provide detailed insights that are critical for identifying and understanding external PCI vulnerabilities:
Domain Intelligence: This module comprehensively overviews an organization's digital presence, including DNS Intelligence (Domain Record Analysis, Domain Name Permutations, Web3 Domains), Email Intelligence, WHOIS Intelligence, and Subdomain Intelligence.
Example: Through Subdomain Intelligence, ThreatNG can identify "APIs on Subdomains". If these APIs handle payment data, their discovery is vital for External PCI Validation, ensuring they are included in the CDE's security scope and subjected to secure coding practices (PCI DSS 6.5.1).
Example: When ThreatNG performs a "Default Port Scan" as part of its Subdomain Intelligence, it identifies externally exposed ports. Suppose sensitive ports like those for databases (e.g., SQL Server, MySQL) or remote access (e.g., RDP, SSH) are found to be open externally. In that case, this directly indicates potential unauthorized access points that must be documented as part of the External PCI Validation and secured with firewalls (PCI DSS 1.2.1).
Sensitive Code Exposure: This module discovers sensitive information within public code repositories.
Example: If ThreatNG finds "Code Secrets Found" such as API keys (e.g., Stripe API key) or cloud credentials (e.g., AWS Access Key ID Value) in a public repository, these represent potential backdoor access points to systems within or connected to the CDE. This provides critical data for External PCI Validation, demanding immediate credential revocation and secure development practices (PCI DSS 6.6).
Cloud and SaaS Exposure: ThreatNG discovers "Sanctioned Cloud Services," "Unsanctioned Cloud Services," "Cloud Service Impersonations," and "Open Exposed Cloud Buckets" across major providers.
Example: Discovering an "Open Exposed Cloud Bucket" through Cloud and SaaS Exposure directly reveals an unintended storage location that might contain CHD. This immediately becomes a critical piece of External PCI Validation, highlighting the need to restrict access based on need-to-know (PCI DSS 7.2.1) and ensure unreadable stored PAN (PCI DSS 3.4.1).
Intelligence Repositories (DarCache)
ThreatNG's continuously updated intelligence repositories provide vital context for enriching External PCI Validation by providing threat context and vulnerability details:
Dark Web (DarCache Dark Web): This includes "Compromised Credentials (DarCache Rupture)" and "Ransomware Groups and Activities (DarCache Ransomware)".
Example: "DarCache Rupture" (Compromised Credentials) identifies leaked usernames and passwords. If these credentials belong to personnel with CDE access, this intelligence is immediately critical for External PCI Validation, as it indicates a direct pathway for unauthorized access (PCI DSS 8.3.1).
Vulnerabilities (DarCache Vulnerability): This includes NVD (DarCache NVD), EPSS (DarCache EPSS), KEV (DarCache KEV), and Verified Proof-of-Concept (PoC) Exploits (DarCache eXploit).
Example: "DarCache KEV" identifies "Vulnerabilities actively exploiting in the wild". Suppose ThreatNG detects an internet-facing asset (identified as part of the CDE's external footprint) with a KEV vulnerability. In that case, this intelligence immediately highlights a proven threat for the CDE, mandating rapid patching prioritization (PCI DSS 6.2.3). "DarCache eXploit" provides direct links to PoC exploits, enabling security teams to reproduce vulnerabilities and understand their real-world impact to develop effective mitigation strategies, enhancing External PCI Validation.
Working with Complementary Solutions
ThreatNG's capabilities create powerful synergies when combined with other cybersecurity solutions, significantly enhancing an organization's efforts in External PCI Validation.
Vulnerability Management (VM) Platforms: ThreatNG's external assessment capabilities, particularly its identification of "Critical Severity Vulnerabilities Found" and "High Severity Vulnerabilities Found" on external subdomains, provide a crucial external perspective that complements VM platforms.
Example: ThreatNG can flag an exposed web application with a critical vulnerability. This External PCI Validation insight can then be pushed to a VM platform to initiate deeper, authenticated scans of the application's internal components. This combined approach ensures that external and internal vulnerabilities that could expose the CDE are identified and prioritized for remediation, supporting PCI DSS 6.2.3 (addressing security vulnerabilities) and 11.3.1 (annual external penetration testing).
Security Information and Event Management (SIEM) Systems: ThreatNG's findings from its various assessment modules can be integrated into a SIEM.
Example: Details about "Admin Page References" or "Custom Port Scan" results, revealing unexpected open ports on external interfaces, can be fed into the SIEM. The SIEM can then correlate these external insights with internal log data to detect suspicious access attempts or activities targeting these newly identified or unmanaged attack surface components, supporting PCI DSS 10.2.1 (logging access to system components) and 10.6.1 (monitoring and responding to security alerts).
Cloud Security Posture Management (CSPM) Tools: ThreatNG's "Cloud and SaaS Exposure" capability identifies externally exposed cloud resources and misconfigurations.
Example: ThreatNG might discover an "Open Exposed Cloud Bucket" potentially containing CHD. This External PCI Validation insight can trigger a more granular internal scan by a CSPM tool to confirm data presence, assess misconfigurations, and ensure access controls are aligned with PCI DSS 7.2.1 (restrict access based on need-to-know) and 3.4.1 (render stored PAN unreadable). The CSPM tool can continuously monitor the cloud environment for new exposures, improving overall External PCI Validation.
Digital Risk Protection (DRP) Solutions: ThreatNG's "Brand Damage Susceptibility" and "BEC & Phishing Susceptibility" assessments, which include identifying "Domain Name Permutations - Taken" and "Dark Web Presence", align closely with the broader scope of DRP.
Example: ThreatNG's "Domain Name Permutations - Taken with Mail Record" discovery provides high-confidence intelligence about potential phishing infrastructure. This External PCI Validation insight can be fed into a DRP solution to monitor these domains for active campaigns and block them, significantly reducing the risk of social engineering attacks that could compromise CDE access (PCI DSS 5.4.1).
