Cost Reduction Strategies for PCI DSS ASV Scanning
Discover 9 proven strategies to reduce PCI DSS ASV scan costs without risking compliance. Shrink scope, avoid rescans, and choose smarter.
PCI vulnerability scanning mandates that all external-facing IPs, FQDNs, and CDE-adjacent systems are submitted to your ASV before scanning begins. Temporarily adjust dynamic protection systems; IPS, rate-limited WAFs, volume-based shun rules; that would block scan traffic and trigger an inconclusive result. Coordinate with your hosting provider for externally hosted components. Correct preparation eliminates the most common causes of first-time scan failure under PCI DSS 4.0.1 Requirement 11.3.2.
PCI vulnerability scanning; specifically external ASV scanning; is the process of having a PCI SSC-listed Approved Scanning Vendor probe your Internet-facing infrastructure for known vulnerabilities and misconfigurations. It’s mandated under PCI DSS 4.0.1 Requirement 11.3.2 for any merchant or service provider with an Internet-facing cardholder data environment (CDE).
The short version: if external-facing systems touch or provide a path to your CDE, they must be scanned; at minimum every 90 days; and a passing certificate issued by a PCI SSC-listed ASV is what your acquirer accepts as evidence.
Preparing that infrastructure correctly isn’t optional. An unprepared environment is the single most common reason scans return inconclusive or fail on the first run.
The scan customer; that’s you; is responsible for defining scope. The ASV scans what you tell them to scan. If a compromised IP isn’t in scope and an attacker gets in through it, liability sits with you, not the ASV.
Per the ASV Program Guide, your scope submission must include:
The most common scoping mistake: submitting only the primary domain and forgetting subdomains, staging environments left publicly accessible, or mail server IPs that don’t immediately appear in a standard DNS lookup. The ASV will perform forward/reverse DNS lookups on common hostnames; www, mail, ftp; and flag any components they find that you didn’t provide. Better to include them yourself upfront.
This is where most first-time scan failures originate. ASV scans are high-volume by design; they generate a lot of traffic quickly to complete efficiently. That behaviour routinely triggers active protection systems (IPS, WAF with rate limits, volume-based firewall rules) that were built to detect exactly that pattern.
The result is an inconclusive scan. Under ASV Program Guide Section 7.6, an unresolved inconclusive scan must be reported as a failed scan.
System Type | Interference Risk | Action Required |
|---|---|---|
IPS dropping traffic from IP after port-scan detection | High | Temporarily set to monitor/log only for scan window |
WAF blocking IPs after request-rate threshold | High | Configure to allow non-attack traffic from ASV source |
Spam filters blacklisting IPs after SMTP probing | Medium | Exclude ASV IP range from automated blacklisting |
QoS devices throttling traffic on volume anomalies | Medium | Temporarily lift thresholds during scan window |
Network controls shunning IPs after detected port scan | High | Disable shunning for scan duration |
Static firewall rules, standard IDS (log-only mode), antivirus, VPN credential rejection, and application-layer WAF rules that block SQL injection but let other traffic through — these don’t interfere with the scan and don’t require modification.
Critical nuance: Temporary configuration changes do not mean whitelisting the ASV or giving it elevated access. The intent is that the ASV sees the same network view an attacker would see — but without being dynamically blocked mid-scan. You’re not opening anything new; you’re preventing automated defences from distorting the scan result.
If any part of your CDE sits with a hosting provider, cloud host, or ISP, that provider’s active protection systems can also interfere. The ASV Program Guide is explicit: you must coordinate with your provider to allow the scan to complete.
Two options exist for hosted environments:
If you’re on shared hosting or a multi-tenant environment, confirm with your provider which option applies before scheduling your scan. Don’t assume they’ve handled it.
Load balancers present a specific issue: if an ASV scan is distributed across load-balanced nodes sequentially, different scan packets may reach different backend servers. This can cause an incomplete picture of the environment.
The scan customer is responsible for coordinating with the ASV so the load balancer configuration is understood and accounted for before scanning starts. Disclose load balancers in your pre-scan communication.
For virtualised environments; virtual machines, hypervisors, virtual appliances; each Internet-facing virtual component that connects to or provides a path into the CDE must be included in scope. Virtual hosts aren’t exempt from Requirement 11.3.2.
There’s no regulatory requirement to schedule scans during off-hours, but it’s best practice. ASV scans should be conducted:
The temporary configuration changes needed to remove interference should be in place only for the duration of the scan. The shorter that window, the lower your exposure.
A failing scan isn’t the end of the process; it’s the start of remediation. Under PCI DSS 4.0.1, the process is straightforward: fix the vulnerabilities flagged in the scan report, then request a rescan.
With Secusy ASV, unlimited rescans are included in every package. There are no additional charges when remediation takes more than one attempt; which it often does. Fix the issue, request a rescan, and the process continues until a passing certificate is issued.
If a scan is inconclusive rather than failing (because of interference), the ASV and scan customer work together under Section 7.6 of the ASV Program Guide to resolve the issue; whether through a new scan after config changes, written evidence that no blocking occurred, or an agreed alternative method.
Every 90 days from your last passing scan. That’s the 90-day window established under PCI DSS 4.0.1 Requirement 11.3.2; not calendar quarters. If you pass on 15 March, your next scan must pass by 13 June.
Additional scans are required after significant changes to your environment under Requirement 11.3.2.1. New public-facing infrastructure, major server changes, or CDE expansion all trigger an out-of-cycle scan requirement.
For more detail on scan frequency and timing rules, see our full guide on PCI ASV scanning services.
Preparation takes less time than dealing with a failed scan. Get your scope defined, your active protections adjusted, and your hosting provider aligned; then book your scan.
Secusy ASV is PCI SSC-listed, starts at $80/year for a single IP, includes unlimited rescans, and delivers your pass certificate within 24 hours. No enterprise complexity. No surprise costs.