External Network Penetration Testing: Expose What Attackers See First
Your Perimeter Has More Attack Surface Than You Think
Your firewall is configured. Your VPN is live. Your domains are registered. But does any of that mean your perimeter is actually secure?
External network penetration testing answers that question the way an attacker would, by attempting to get in. We enumerate your internet-facing assets, identify exploitable weaknesses across exposed services, chain low-severity findings into realistic attack paths, and deliver a report that tells you exactly what’s vulnerable and how to fix it. Not a scan. An adversarial simulation conducted by certified pentesters who hold credentials in Communication & Network Security, Ethical Hacking, and ISO/IEC 27001 Information Security.
Engagements start from $4,500. See our pricing page for a full tier breakdown.
What We Test: Your Full External Attack Surface
Most organizations don’t have a complete inventory of their own perimeter. Forgotten subdomains, legacy VPN endpoints, misconfigured mail servers – these are real entry points, and automated scanners routinely miss the exploitability context that matters.
Exposed service enumeration
TCP/UDP port scanning across all in-scope IP ranges to identify services that are either internet-accessible when they shouldn’t be or are running software versions with known CVEs.
Subdomain discovery and takeover testing
DNS brute-forcing combined with certificate transparency log analysis and CNAME takeover checks for dangling records pointing to decommissioned cloud resources. A misconfigured DNS record is all it takes to hand an attacker a trusted subdomain on a silver platter.
Unpatched and end-of-life systems
Internet-facing servers and network appliances running software with public exploits, VPN gateways, RDP services, web servers, and management interfaces running unsupported OS versions.
VPN and remote access endpoints
Authentication bypass testing, credential stuffing exposure assessment, split tunneling weaknesses, and deprecated IKE or SSL VPN implementations still listening on external interfaces.
Mail server and webmail configuration
SPF, DKIM, and DMARC misconfiguration; open relay testing; and external Outlook Web Access or Exchange exposure that could facilitate domain spoofing.
Credential exposure on external-facing assets
Login portal brute-force resistance testing, default credential checks on management interfaces, and correlation of publicly available breach data against your domains to identify reused credentials still in active use.
Administrative interface exposure
Router management panels, firewall consoles, and server administration tools reachable directly from the internet, often on non-standard ports that scanners skip.
Cloud perimeter assets (where in scope)
Public cloud storage buckets, misconfigured load balancers, and storage endpoints tied to your IP ranges or domain registrations.
Real-World Attack Scenarios We Replicate
Each scenario below reflects patterns we’ve encountered across 2,500+ engagements with clients across fintech, healthcare, e-commerce, and SaaS.
How We Conduct the Assessment
Our methodology is manual-led, PTES-aligned, and built around what’s actually exploitable, not just what automated tooling detects.
PHASE 01
Passive OSINT & footprinting
We begin with passive OSINT and active reconnaissance to build a complete picture of your external footprint, including assets you may not know are exposed. Certificate transparency logs, DNS records, WHOIS history, leaked credential databases, and public cloud asset enumeration all feed into scope confirmation before active testing begins.
PHASE 02
Service enumeration & vulnerability identification
Full TCP/UDP port scanning across all in-scope ranges, version fingerprinting, and CVE correlation against discovered services. Automated tooling supports discovery, human judgment decides what’s worth pursuing and in what order.
PHASE 03
Exploitation & attack path chaining (manual-first)
We move into service-specific exploitation attempts, chaining low-severity findings into realistic multi-step attack paths wherever the evidence supports it. Every finding is manually validated before it appears in the report. We don’t deliver scanner output dressed up as a pentest.
PHASE 04
Reporting & remediation guidance
Each finding is documented with CVE references where applicable, CVSS scoring, proof-of-concept evidence, reproduction steps, and remediation guidance specific to your environment, not copy-pasted from a scanner template.
PHASE 05
Retest & closure
Once you’ve remediated, we retest the specific vulnerabilities flagged in the original report at no additional charge within the agreed retest window. We verify fixes are effective, update finding statuses, and issue a final remediated report version, which for PCI DSS and SOC 2 auditors is often the document they actually need.
Frameworks: PTES · OWASP Testing Guide · NIST SP 800-115 · MITRE ATT&CK · CIS Controls
Compliance Requirements This Engagement Satisfies
External network penetration testing isn’t optional for regulated industries. It’s a named control requirement under several frameworks.
PCI DSS v4.0
Requirement 11.3.2 mandates external penetration testing of the cardholder data environment boundary at least annually and after significant infrastructure changes. Our report documentation is structured to satisfy QSA evidence requests for this requirement.
SOC 2 Type II (CC6.1, CC6.6)
Common Criteria around logical access controls and network boundary protection regularly require external penetration testing evidence to satisfy auditor inquiries during Type II assessments.
ISO 27001:2022
A.8.8 and A.8.20 address technical vulnerability management and network security controls respectively. Our CEO holds ISO/IEC 27001 Information Security Associate certification, and engagements are scoped with ISMS alignment in mind.
HIPAA §164.308(a)(8)
The technical evaluation requirement under the Security Rule applies to internet-facing systems that process or transmit ePHI. An external pentest directly satisfies this evaluation obligation for your perimeter assets.
What You Receive
Every engagement delivers a structured report package, not just a vulnerability list.
Executive summary
Risk posture overview written for non-technical leadership and board-level readers who need the business impact framing, not the CVE numbers.
Technical findings report
Each vulnerability documented with CVE references where applicable, CVSS scoring, proof-of-concept evidence, reproduction steps, and remediation guidance specific to your environment, not copy-pasted from a scanner template.
Attack path documentation
Where findings chain together into a realistic compromise scenario, we map the full path from initial external access through to potential internal impact.
Remediation priority matrix
Findings ranked by actual exploitability and business context, not raw CVSS score. A 9.8 CVSS finding on an isolated system ranks lower than a 6.5 that opens a path to your payment infrastructure.
Letter of attestation
For use with auditors, clients, or procurement teams requiring documented evidence of penetration testing conducted by certified professionals.
Free retest
Once you’ve remediated, we retest and re-issue the report at no extra charge. For PCI DSS and SOC 2 auditors, the remediated version is often the document they actually need.
Download our sample penetration test report to see the exact format and depth before you commit.
Frequently asked questions
What does external network penetration testing cover?
Our external network pentest covers: TCP/UDP port scanning of internet-facing IP ranges, subdomain discovery and takeover testing (DNS brute-forcing, CNAME takeover checks), identification of unpatched and end-of-life systems, VPN and remote access endpoint testing (credential stuffing exposure, deprecated IKE/SSL VPN), mail server configuration testing (SPF, DKIM, DMARC, open relay), credential exposure on external login portals, administrative interface exposure on non-standard ports, and cloud perimeter asset enumeration (public S3 buckets, misconfigured load balancers).
Is external penetration testing required for PCI DSS compliance?
Yes. PCI DSS v4.0 Requirement 11.3.2 mandates external penetration testing of the cardholder data environment boundary at least annually and after significant infrastructure changes. Our report documentation is structured to satisfy QSA evidence requests for this requirement.
How much does external network penetration testing cost?
Engagements start from $4,500. The final price is scoped by IP range size, domain count, and the complexity of exposed services. We return a fixed-price quote within 24 hours of receiving your IP ranges and domains — no ambiguous estimates.
Is a free retest included?
Yes. Once you have remediated the findings, we retest the specific vulnerabilities flagged in the original report at no additional charge within the agreed retest window. We verify fixes are effective, update finding statuses, and issue a final remediated report version — which for PCI DSS and SOC 2 auditors is often the document they actually need.
What is the difference between external and internal network penetration testing?
External network penetration testing simulates an attacker with no prior access — testing only what is reachable from the internet. Internal network penetration testing simulates a threat actor already inside your network (compromised endpoint or malicious insider) and focuses on lateral movement, Active Directory attack paths, and segmentation validation. Both are typically required for PCI DSS compliance (Requirement 11.3).
How long does an external network pentest take?
Most engagements complete within 3–5 business days from the agreed testing window start, depending on the size of the IP range and domain count. We confirm the timeline during scoping, and rush engagements can be accommodated depending on availability.
What do you need from our team to get started?
Your list of external IP ranges and domains. That’s it to start — we’ll return a fixed-price quote within 24 hours. Before testing begins we also confirm a testing window, agree on rules of engagement in writing, and sign an NDA if required.
Can you test in a production environment?
Yes, routinely, with agreed testing windows, safe testing controls, and communication protocols to minimize operational impact. All rules of engagement are documented before testing begins.