How to Pass a PCI Compliance Scan: The ASV Scan Guide (Requirement 11.3.2)

To pass a PCI compliance scan (the quarterly external ASV scan), no internet-facing IP address or domain in your scope can have a vulnerability with a CVSS base score of 4.0 or higher, or any finding the ASV Program Guide treats as an automatic failure. In practice you pass by declaring the full scope, patching and hardening everything that faces the internet, letting the scanner through your IPS and WAF, disputing false positives with evidence, and scanning early enough in each quarter to fix and rescan.

This guide shows how to pass a PCI ASV scan first time, and keep passing every quarter, if your SAQ or Report on Compliance includes PCI DSS v4.0.1 Requirement 11.3.2. If you would rather have the scans run and managed for you, see our ASV scan service.

Key takeaways

• A passing scan means no in-scope finding scored CVSS 4.0 or higher and no automatic failures.
• You need a passing external scan in every three-month period, run by a PCI SSC Approved Scanning Vendor.
• Most failures come from out-of-date software, weak TLS, exposed services and incomplete scope.
• A failed scan is not a failed quarter if you leave time to fix, dispute and rescan.
• Accurate scope is your responsibility, not the ASV’s.

What is a PCI ASV scan?

A PCI ASV scan is an automated external vulnerability scan of your internet-facing systems, run by an Approved Scanning Vendor (ASV): a company the PCI Security Standards Council has qualified to perform these scans with a tested scan solution. It is how you meet Requirement 11.3.2, and the ASV’s attested report is the evidence your acquirer or assessor accepts.

The ASV follows the Council’s ASV Program Guide, available in the PCI SSC document library. The Guide sets what must be scanned, what counts as a failure, how disputes work and what the report looks like. Each report has three parts: the Attestation of Scan Compliance, a summary by component, and the detailed vulnerability findings.

What are the PCI ASV scan requirements?

Requirement 11.3 covers both external and internal scanning. Only the quarterly external scans have to be run by an ASV.

Whether you need ASV scans depends on how you validate. Almost every validation route that involves an internet-facing system includes them, including SAQ A for the website that hosts or redirects to your payment page. Our guide to which PCI SAQ you need explains the differences, and our free PCI compliance check suggests your likely SAQ.

What makes an ASV scan pass or fail?

A scan passes when every in-scope component is free of vulnerabilities scored CVSS 4.0 or higher, apart from any the ASV has accepted on dispute. Some findings fail regardless of score, including SQL injection, cross-site scripting, operating systems no longer supported by their vendor, databases reachable from the internet, and SSL or early TLS.

The ASV may also raise “special notes” for things such as remote access software or browsing of directories. These do not fail the scan on their own, but you must confirm the business need and how the service is secured.

Why do PCI ASV scans fail?

The same handful of causes account for most failed scans. Each has a straightforward fix.

How do you pass a PCI compliance scan?

Follow the same routine every quarter and a clean PCI ASV scan becomes the norm rather than a scramble.

1. Confirm the scope. List every internet-facing IP address and domain that is part of, or provides a path into, your cardholder data environment. Check DNS, cloud accounts and third-party hosting for anything missed. Our PCI DSS scoping guide explains how to set the boundary.
2. Run a pre-scan. Scan with your own tool, or through managed vulnerability scanning services, a few weeks before the official scan.
3. Fix the obvious. Patch, disable weak TLS, close unneeded ports and retire unsupported systems.
4. Prepare the network. Allowlist the ASV’s scanner in your intrusion prevention system and web application firewall. The Program Guide requires the scan to see your systems as they really are.
5. Scan early in the quarter. A first scan in the opening weeks leaves time to recover from a failure.
6. Triage the results. Sort each failure into a real vulnerability, a false positive, a finding covered by a compensating control, or an item that is out of scope.
7. Fix, dispute and rescan. Rescan until you have a passing result for every component, then store the attestation.
8. Scan again after significant change. A new web server, firewall or hosting provider needs its own external scan under 11.3.2.1.

How long does an ASV scan take, and how often do you need one? The scan itself is automated, so its length depends mainly on how many IP addresses and domains are in scope; for a small scope it usually takes hours rather than days. What takes time is the cycle around it, because fixing, disputing and rescanning can run to several weeks. You need a passing external scan at least once every three months, plus a further scan after any significant change.

How do you dispute a false positive?

You submit evidence to the ASV through its portal, and the ASV decides whether to accept it. Good disputes are specific. For a backported patch, supply the vendor’s security advisory and the installed package version that contains the fix. For a component you believe is out of scope, show why it has no route into the cardholder data environment.

Some findings can be addressed with a documented compensating control, subject to the ASV’s review. Our guide to PCI DSS compensating controls explains what makes one credible.

What happens if you fail an ASV scan?

A failed scan only becomes a compliance problem if the quarter ends without a passing result. The ASV can combine several reports to show that every component passed within the same three-month period.

For an annual assessment, your assessor expects four passing quarterly scans. For initial compliance, fewer are acceptable if the most recent scan passed, you have a documented process for scanning every three months, and earlier failures were corrected and rescanned. A missed quarter cannot be recovered afterwards, so treat the scan date as a deadline, not a target.

Is a free PCI compliance scan enough?

Only if an ASV runs it. Free external scanners are useful for pre-scans, but their output does not meet Requirement 11.3.2. Some acquirers and payment providers include ASV scans in their compliance portals, so check what your merchant agreement already covers before buying a separate subscription.

Is an ASV scan the same as a penetration test?

No. An ASV scan checks, automatically and every quarter, whether known weaknesses are visible from the internet. A penetration test uses a skilled tester to find out what an attacker could actually achieve, and Requirement 11.4 requires internal and external tests at least every 12 months and after significant change. Our PCI DSS penetration testing covers those tests, including segmentation. For the wider difference, see penetration testing vs vulnerability scanning.

Getting help

Sovereign Secure is not an ASV. We deliver quarterly scans through our PCI SSC Approved Scanning Vendor partner and, as a PCI SSC-approved Qualified Security Assessor (QSA) company, manage the scope, results, disputes and rescans around them. That means your scans line up with your next PCI compliance audit. For how scanning fits your overall budget, see our guide to PCI compliance cost.

Not sure whether your SAQ includes ASV scans at all? Our free PCI compliance check takes about five minutes and gives you your likely SAQ and a fix list. If your SAQ does include them, our managed ASV scans take the quarterly cycle off your hands.