Understanding PCI ASV 4.0 scans.

In the intricate landscape of cyber-security, safeguarding payment card transactions remains a top priority. Under the PCI Data Security Standard (PCI DSS), PCI ASV scan are executed by certified vendors, aiming to identify externally present vulnerabilities and ascertain that organizations are effectively protecting cardholder data.

PCI Approved Scanning Vendor or known as PCI ASV for short are organisations that are recognised and certified by a governing body called the PCI Security Standards Council.

PCI ASVs, in a way, can be regarded as an authority that enforces compliancy of organisations that must comply with PCI SSC’s regulations to ensure cardholder data are kept safe by organisations who process, transmit or store cardholder data.

Navigating the Shift to ASV Scans v4.0

As part of the ASV Scan v4.0 update, payment page scripts that are loaded and executed in the consumer’s browser is an additional check.

Scripts that are loaded and executed on the payment page can pose security threats. Without the entity's knowledge, these scripts can be modified or given the capability to load additional external scripts, such as advertising, tracking, or tag management systems. While some scripts may appear harmless, attackers could exploit them to upload malicious scripts, which can then read and exfiltrate account data from the consumer's browser. It's crucial to comprehend the purpose of all scripts on the payment page to ensure they're indispensable. This understanding helps reduce the number of scripts vulnerable to tampering.

The ASV scan solution chosen should be proficient at identifying these scripts. If it recognizes any known vulnerabilities or exploits tied to the scripts, the solution must flag their presence.and executed in the consumer’s browser, or detects any known exploits or vulnerabilities related to the scripts,the ASV scan solution must note the presence of such scripts.

The Role and Relevance of CVSS v3.1 in ASV Vulnerability Scoring

Since the introduction of the ASV Program Guide 3.2r1 in December 2022, the use of CVSS version 3.1 for scoring vulnerabilities has been mandated.

Understanding the severity and implications of cyber-security vulnerabilities is paramount. The Common Vulnerability Scoring System (CVSS) serves this purpose.

Transitioning to CVSS v3.1 introduces several vital improvements:

  • Severity over Risk: A salient shift in CVSS v3.1 is its focus on measuring severity instead of risk. The CVSS v3.1 User Guide underlines that CVSS quantifies the severity of vulnerabilities and should not be the sole metric to assess risk
  • Comprehensive Risk Assessment: The new version challenges the misconception of relying solely on the CVSS Base Score for risk assessment, emphasizing a more holistic approach to risk evaluation.
  • The CVSS Extensions Framework: Introduces a standardized method for expanding CVSS. It permits scoring providers to incorporate more metrics and metric groups while maintaining the official Base, Temporal, and Environmental Metrics.

Best Practices for Navigating the PCI ASV Landscape

Transitioning to new standards and practices can be a daunting task. However, with a strategic approach and clear focus, organizations can navigate this transition smoothly. Here are some best practices to consider:

Continuous Monitoring and Feedback

  • Implement real-time monitoring systems to keep track of your digital infrastructure.
  • Regularly review and update your security measures to address new threats and vulnerabilities.
  • Encourage feedback loops within teams to identify potential areas of improvement.

Engage with External Experts

  • Collaborate with Qualified Security Assessors (QSA) for insights and guidance on PCI DSS compliance.
  • Regularly consult with your Approved Scanning Vendor (ASV) to ensure your scans are comprehensive and tailored to your specific needs.
  • Attend industry webinars, workshops, and conferences to stay updated on the latest trends and best practices.

Foster a Culture of Cyber-security

  • Ensure all team members, especially those handling cardholder data, undergo regular training on PCI DSS requirements and best practices.
  • Promote a proactive approach to cyber-security, where every team member is vigilant and aware of potential threats.
  • Use real-world incidents as case studies to highlight the importance of adherence to security protocols.

Embrace Technology Solutions

  • Leverage automated compliance solutions that can monitor adherence to PCI DSS standards in real-time.
  • Integrate threat intelligence platforms to stay informed about emerging threats specific to your industry.
  • Implement incident response systems to ensure rapid and effective response in case of security breaches.



In the rapidly evolving domain of cyber-security, staying abreast of industry standards is imperative. The updates to PCI DSS, ASV Program Guide, and CVSS frameworks reflect the industry's dedication to bolstering defenses against escalating cyber threats. By understanding, embracing, and strategically implementing these changes, organizations can not only ensure compliance but also fortify their defense mechanisms against potential cyber adversaries.