External Vulnerability Scanning

Find and fix vulnerabilities in external facing assets. Proactive protection from emerging threats. Automated to save you time.

Protect your external systems with ease

New vulnerabilities are discovered daily, so even if no changes are deployed to your systems, they could become vulnerable overnight. Intruder's external vulnerability scanner makes it easy to continuously secure your systems helping you find and fix security weaknesses before they can be exploited.

new vulnerabilities everyday

What is an external vulnerability scanner?

An external vulnerability scanner is a tool that finds security issues or weaknesses in external-facing systems, also known as your perimeter.

This includes web applications, ports, and any assets accessible from the internet. External scanning simulates the activities of a remote attacker to check for vulnerabilities such as missing patches, misconfigurations, common mistakes, encryption weaknesses, information leakage, unintentionally exposed systems, and remote vulnerable software.

Conducting external vulnerability scanning gives teams ongoing insight into how their perimeter might be vulnerable, which is crucial for proactively preventing security breaches.

How to scan your perimeter with Intruder


Add your targets

Add your external targets by URL, IP or integrate your cloud accounts. Kick off a scan in a few clicks.


Review your results

Assess issues prioritized by business context. Send tickets directly to your team for remediation within hours of your scan.


Verify your fixes

Quickly rescan specific issues to check if your fixes worked. Set up automated scans for continuous security.

See how easy external vulnerability scanning can be

Save time with automated external vulnerability scanning

Schedule scans at flexible intervals to find vulnerabilities such as security misconfigurations, injection flaws, and more. Set up cloud integrations to automate discovery and scanning of new external assets.

automated scanning

Scanning that keeps you protected from the unknown

With new threats discovered every day, Intruder’s proactive threat response features have you covered. Emerging threat scans notify you as soon as new vulnerabilities are discovered. Rapid response automatically checks your systems for the latest issues being exploited in the wild before automated scanners can.

Fix the issues that make your perimeter most vulnerable

Intruder filters out the noise and intelligently prioritizes your results by business context. Receive remediation advice, measure your cyber hygiene, and track how long it takes to fix issues.

Close the door on hackers

Your network is constantly changing and keeping on top of what is and isn't exposed to the internet, as well as what is exposed and shouldn't be, is like a full-time job.

External network monitoring with Intruder gives you continuous visibility of your perimeter and puts you in control of your attack surface.

How often should you scan?

The time between a vulnerability being discovered and hackers exploiting it is narrower than ever – just 12 days. We explain why continuous vulnerability scanning has become essential and how you can best implement it.

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What does Intruder’s external scanner check for?
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Intruder’s external vulnerability scanner checks your systems for web-layer security problems (such as SQL injection and cross-site scripting), 140,000+ infrastructure weaknesses (such as remote code execution flaws), and other security misconfigurations (such as weak encryption configurations, and systems which are unnecessarily exposed). Learn more about what checks we run.

How do emerging threat scans work?
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Intruder’s external vulnerability scanner includes proactive checks for emerging threats. This means when a new vulnerability is discovered in software deployed on your perimeter, Intruder scans your systems and alerts you to newly discovered vulnerabilities automatically. This kind of proactive action is essential for businesses that don’t have processes in place to research the latest threats and manually run scans for them. Learn more.

What is the difference between external and internal vulnerability scanning?
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External vulnerability scanning assesses your internet-facing infrastructure for known vulnerabilities that an attacker, who doesn’t have access to your organization's private networks, could exploit.

On the flip side, internal vulnerability scanning is concerned with finding weaknesses in your internal endpoints, which are typically hidden behind a firewall and only accessible by your employees or trusted partners.

Learn more about the differences between internal vs external vulnerability scanning.

Should I start with external vulnerability scanning or web application scanning?
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Ideally you should do both. That being said, the majority of data breaches are caused by hackers exploiting vulnerabilities that are visible from the internet, so you want to make sure that your external systems are protected from the outset. External scanners are also able to detect multiple web-layer issues, so if you’re new to vulnerability scanning, they are often the best tools to start with.

How often should I run vulnerability scans?
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We believe that a continuous approach is best. Continuous scanning reduces the time to find and fix vulnerabilities, delivers rich threat data and remediation advice, and minimizes your risk by prioritizing threats according to the context of your business needs. Intruder makes it easy to adopt a continuous approach. Learn more.

Can I perform internal network scanning using Intruder?
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Yes, it’s possible to use Intruder for internal vulnerability scanning. Our internal scanner is agent-based, so you’ll need to install a piece of software on each host you’re planning to scan, either Windows, Linux or MacOS. To learn more about it, please read our help article.  

Can I scan behind a web app login?
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Yes, you can carry out authenticated application scans using Intruder. This includes web apps, APIs, and single page applications (SPAs).

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