Cybersecurity Foundations Series (Part 5)
Lesson 5: Implementing Vulnerability Scanning Methods
(CySA+ CS0-003)
So far in this series, we’ve built the structure of security operations.
Lesson 1 explained why security exists — governance and risk.
Lesson 2 showed us who is attacking — threat actors and intelligence.
Lesson 3 defined what we’re protecting — systems, identity, and logging.
Lesson 4 explained how we operate efficiently — automation, SIEM, and SOAR.
Now Lesson 5 answers a different question:
How do we find weaknesses before attackers do?
Because detection is reactive.
Vulnerability scanning is proactive.
And if you’re studying for Security+ or CySA+, this is where you start thinking like a real analyst.
Why Compliance Comes First
Most organizations don’t scan randomly.
They scan because frameworks and regulations require it.
You’ll see names like:
NIST
ISO 27001
CIS Benchmarks
OWASP
PCI DSS
These define what “secure” should look like.
CIS Benchmarks
Tech Def:
A set of consensus-based secure configuration guidelines developed to harden operating systems and applications.
Simple Def:
A secure setup checklist for systems.
Example
If a Windows server allows anonymous SMB access, CIS would flag that as insecure.
The benchmark would recommend disabling it.
Security+ expects you to recognize CIS as a configuration best practice.
CySA+ expects you to use baselines when validating systems.
OWASP Top 10
OWASP focuses on web application risks like:
Broken Access Control
Injection
Security Misconfiguration
Server-Side Request Forgery
Tech Def:
A ranked list of the most critical web application vulnerabilities.
Simple Def:
The most common web app mistakes attackers exploit.
Example
A login form that doesn’t properly sanitize input could allow SQL injection.
That’s an OWASP Top 10 issue.
On Security+, you identify it.
On CySA+, you interpret scan results showing it.
PCI DSS
Tech Def:
A global security standard requiring organizations handling credit card data to implement controls and undergo regular assessments.
Simple Def:
If you process credit cards, you must prove you’re secure.
Example
An online store must run quarterly vulnerability scans and fix critical issues to stay PCI compliant.
On exams, remember: compliance can dictate scan frequency.
Vulnerability Scanning
Tech Def:
An automated process that evaluates systems, applications, and devices for known security weaknesses using a vulnerability database.
Simple Def:
A tool that checks your systems for known problems.
Example
If your server is running an outdated version of Apache with a known exploit, the scanner will flag it.
Important distinction:
Vulnerability scanning identifies weaknesses.
Penetration testing attempts to exploit them.
Security+ tests the difference.
CySA+ expects you to apply it.
Internal vs External Scanning
External Scanning
Tech Def:
Assessment performed from outside the organization’s network perimeter.
Simple Def:
What can someone on the internet see?
Example
An external scan finds that port 3389 (RDP) is exposed publicly.
That’s high risk.
External findings often require urgent remediation.
Internal Scanning
Tech Def:
Assessment performed from within the organization’s network, often with authenticated access.
Simple Def:
What can someone inside see?
Example
An internal scan reveals shared folders accessible to “Everyone.”
An attacker who already gained access could escalate from there.
Internal scanning simulates post-compromise movement.
Credentialed vs Non-Credentialed
Credentialed Scanning
Tech Def:
Uses valid authentication credentials to evaluate patch levels, configurations, and local vulnerabilities.
Simple Def:
The scanner logs in and checks deeply.
Example
A credentialed scan logs into a server and finds that a critical Windows patch is missing.
It sees things an outsider couldn’t.
Non-Credentialed Scanning
Tech Def:
Assessment without authentication.
Simple Def:
Checking from the outside without logging in.
Example
It identifies open ports but cannot determine installed software versions.
Credentialed = deeper visibility.
Non-credentialed = surface visibility.
Agent-Based vs Agentless
Agentless
Tech Def:
Collects vulnerability data remotely using protocols like SSH, WMI, or SNMP.
Simple Def:
No software installed — scan remotely.
Example
The scanner connects via SSH to collect system info.
If firewalls block SSH, the scan fails.
Agent-Based
Tech Def:
Requires installation of software agents on endpoints to gather vulnerability data locally.
Simple Def:
You install a small program that reports vulnerabilities back.
Example
An endpoint agent reports missing patches even when the device is off the corporate network.
Trade-off:
Better visibility — but more management overhead.
Active vs Passive Scanning
Active Scanning
Tech Def:
Directly interacts with systems to enumerate services and test vulnerabilities.
Simple Def:
The scanner probes the system.
Example
Nessus sends packets to determine service versions.
Active scans may affect performance.
Passive Scanning
Tech Def:
Identifies vulnerabilities by observing traffic without direct interaction.
Simple Def:
Watching quietly instead of probing.
Example
Detecting cleartext passwords being transmitted over HTTP.
Passive scanning is useful in sensitive environments.
Criticality Ranking
Tech Def:
A standardized scoring mechanism used to prioritize vulnerability remediation.
Simple Def:
A severity score to decide what to fix first.
Example
A “Critical” vulnerability on a public web server gets fixed before a “Medium” issue on a test machine.
But context matters.
That’s CySA-level thinking.
Static vs Dynamic Analysis
Static Analysis
Tech Def:
Examination of source code without executing it.
Simple Def:
Reviewing the blueprint.
Example
Finding insecure coding libraries in a web application’s source code.
Dynamic Analysis
Tech Def:
Testing software while it is running.
Simple Def:
Testing the building while people are inside.
Example
Interacting with a live web app to see if input validation fails.
Fuzzing
Tech Def:
Automated injection of malformed or unexpected input to discover vulnerabilities.
Simple Def:
Throwing weird data at a program to see if it crashes.
Example
Sending extremely long input into a login field to see if it triggers a buffer overflow.
Attackers use fuzzing.
Defenders should too.
Configuration Baseline
Tech Def:
A documented minimum security configuration standard used as a reference point.
Simple Def:
The secure starting point for a system.
Example
If your company baseline says RDP must require MFA, any system without MFA is non-compliant.
Baselines turn scanning into measurable security.
Industrial and Operational Technology
Some systems control physical processes:
SCADA
PLCs
Industrial Control Systems
These can’t always handle aggressive scans.
Example
A poorly timed scan against a manufacturing controller could disrupt production.
In critical environments, availability may outweigh aggressive scanning.
CySA+ expects you to recognize operational impact.
The Bigger Picture
Lesson 5 is about structure.
It’s about:
Compliance
Scope
Authentication strategy
Agent decisions
Performance considerations
Risk prioritization
Configuration baselines
Operational awareness
Scanning isn’t just running a tool.
It’s understanding what the results mean.
For Security+ Focus On:
Internal vs external
Credentialed vs non-credentialed
OWASP Top 10
PCI DSS basics
Baselines
For CySA+ Focus On:
Agent-based vs agentless
Active vs passive
Criticality ranking
Static vs dynamic analysis
Fuzzing
Operational technology considerations
Context-driven prioritization
Conclusion
Security isn’t just catching attacks.
It’s reducing weaknesses before they’re exploited.
Lesson 5 teaches that vulnerability scanning is structured, compliance-driven, risk-aware, and context-sensitive.
When governance sets expectations, intelligence identifies threats, logging provides visibility, automation speeds response — vulnerability scanning measures how exposed you actually are.
That’s operational maturity.
And that’s exactly what CompTIA security exams expect you to understand…….
Until the next lesson.