Passive scanning
Passive vulnerability scanning, safe to run in production.
No payloads, no brute forcing, no state changes. Just observation of what your live app already exposes. Run it against prod without a war room.
How passive scanning works
A polite scan you can run any time of day.
Read-only
No state changes, ever
Default scans don't submit forms, don't write data, don't trigger transactional flows. The app behaves exactly the same after the scan as before.
No payloads
No exploit attempts in default mode
Passive scans observe what the server returns. No SQL-injection probes, no XSS payloads, no buffer-overflow attempts. Safe for prod.
Rate-limited
Won't take down your site
Scans are throttled to avoid load spikes. Slower than aggressive scanning, but it means your service stays up.
Same surface
Looks like a regular visitor
Default scan behaves like a polite browser. Reads pages, reads headers, checks TLS, runs DNS lookups. Nothing your CDN would flag.
Deep findings
Catches the categories that matter
TLS, headers, cookies, CORS, DNS, email auth, network exposure, web hygiene. The categories that fail audits, all passively detectable.
AI pentesting available
Active engagement when you need it
For SQL injection, XSS, broken access control, IDOR, the categories that need active exploitation, book an AI pentest. Scoped, time-bounded, non-destructive.
What we observe
The signal you'd never get from logs alone.
- ✓TLS handshake details, cipher suite strength, certificate chain validity
- ✓Every security header the app returns, plus what's missing
- ✓Cookie attributes on every Set-Cookie
- ✓DNS records relevant to security: SPF, DKIM, DMARC, DNSSEC, CAA
- ✓Network surface: open ports (non-intrusive), subdomain takeover candidates
- ✓Page-level web hygiene: vulnerable JS libraries, mixed content, framework leakage
FAQ
Passive vulnerability scanning, explained.
What's the difference between passive and active vulnerability scanning?
Passive scanning observes what your live application already exposes, TLS handshakes, security headers, cookies, DNS records, network surface, without sending crafted payloads or interacting with state-changing routes. Active scanning sends test inputs to find bugs that only show up under interaction (e.g. SQL injection payloads, XSS probes, authentication bypass attempts). Passive is safe to run against production continuously; active needs scoped engagements like Barrion's AI pentesting product.
What categories of issue can passive scanning actually catch?
Passive scanning is the right tool for the OWASP A02 (Cryptographic Failures), A05 (Security Misconfiguration), A06 (Vulnerable and Outdated Components), and A09 (Security Logging and Monitoring Failures) categories. It also catches DNS and email-authentication issues (SPF, DKIM, DMARC, DNSSEC, CAA), network exposure (open ports, subdomain takeover candidates), and framework leakage (server headers, debug pages reachable from the internet).
Will passive scanning trigger my WAF or rate limits?
Generally no. Passive scans look like a polite browser to your CDN and WAF, they read pages, read headers, do DNS lookups, and check certificate chains. Rate-limited and throttled by default. If you operate a particularly aggressive WAF rule set, the scanner's source IPs can be allowlisted, but the vast majority of customers do not need to make any configuration change.
If passive scanning is safe, why does anyone use active scanning?
Because some of the most impactful vulnerabilities only show up under interaction. SQL injection, broken access control, IDOR, business-logic abuse, these require the scanner to send requests that exercise the application's logic, not just observe its surface. Active scanning is essential for those categories. Barrion's recommendation is continuous passive monitoring as the always-on baseline, plus scoped active pentesting (human or AI) before audits and major launches.
Can passive scanning be used as compliance evidence?
Yes for the relevant control families. SOC 2 CC7 (System Operations), ISO 27001 Annex A 8.16 (Monitoring activities), PCI DSS Requirement 11 (Regularly test security systems and processes), and NIS2 ongoing-risk-management requirements all accept automated passive scanning as ongoing-monitoring evidence. For PCI DSS Requirement 11.3 specifically (penetration testing), passive scanning is supplementary to a human pentest, not a replacement.
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