Vulnerability scanning tools (Nessus, OpenVAS) in Cybersecurity - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the primary purpose of vulnerability scanning tools like Nessus and OpenVAS?

Their main purpose is to automatically identify security weaknesses in computer systems, networks, and applications to help prevent cyber attacks.

beginner

Name two popular vulnerability scanning tools.

Nessus and OpenVAS are two widely used vulnerability scanning tools in cybersecurity.

intermediate

How does Nessus differ from OpenVAS?

Nessus is a commercial tool with a free limited version, known for its extensive plugin library and user-friendly interface. OpenVAS is an open-source tool, free to use, with a strong community but sometimes less polished interface.

beginner

What type of vulnerabilities can these tools detect?

They can detect missing patches, misconfigurations, outdated software, weak passwords, and known security flaws in systems and applications.

beginner

Why is regular vulnerability scanning important?

Because new vulnerabilities appear frequently, regular scanning helps organizations find and fix security issues before attackers exploit them.

Which of the following is a free and open-source vulnerability scanning tool?

A OpenVAS

B Nessus

C Wireshark

D Metasploit

OpenVAS is a free, open-source vulnerability scanner, while Nessus is commercial with a free limited version.

What does a vulnerability scanner primarily look for?

A Network traffic speed

B Hardware failures

C User passwords

D Security weaknesses

Vulnerability scanners identify security weaknesses like missing patches or misconfigurations.

Which feature is Nessus especially known for?

A Extensive plugin library

B Email filtering

C Hardware diagnostics

D Open-source code

Nessus has a large plugin library that helps detect many types of vulnerabilities.

Why should organizations run vulnerability scans regularly?

A To backup data

B To improve internet speed

C To find new security issues quickly

D To update software automatically

Regular scans help find new vulnerabilities before attackers can exploit them.

Which of these is NOT typically detected by vulnerability scanners?

A Outdated software

B Physical theft of hardware

C Misconfigured settings

D Weak passwords

Vulnerability scanners focus on software and configuration issues, not physical security.

Explain what vulnerability scanning tools like Nessus and OpenVAS do and why they are important.

Think about how these tools help keep systems safe by finding problems early.

Compare Nessus and OpenVAS in terms of cost, usability, and community support.

Consider price, ease of use, and who maintains the tool.

Practice

1. What is the main purpose of vulnerability scanning tools like Nessus and OpenVAS?

easy

A. To create new software applications

B. To automatically find security weaknesses in systems

C. To manage user accounts and passwords

D. To encrypt data for secure communication

Solution

1. Step 1: Understand the role of vulnerability scanning tools

   These tools scan computer systems to find security weaknesses automatically.

2. Step 2: Compare options with the tool's purpose

   Only To automatically find security weaknesses in systems describes finding security weaknesses, which matches the tool's main function.

3. Final Answer:

   To automatically find security weaknesses in systems -> Option B

4. Quick Check:

   Vulnerability scanning = find security weaknesses [OK]

Hint: Remember: scanning tools find weaknesses automatically [OK]

Common Mistakes:

• Confusing scanning tools with software development tools
• Thinking they manage user accounts
• Assuming they encrypt data

2. Which of the following commands correctly starts a scan using Nessus from the command line?

easy

A. nessuscli scan start

B. openvas --launch

C. scan nessus begin

D. nessus --start-scan

Solution

1. Step 1: Identify correct command syntax for Nessus CLI

   Nessus uses the command line tool nessuscli with subcommands like scan start to begin scans.

2. Step 2: Check each option

   nessuscli scan start matches the correct syntax. Options A, B, and C are incorrect commands. openvas --launch is for OpenVAS, not Nessus.

3. Final Answer:

   nessuscli scan start -> Option A

4. Quick Check:

   Nessus CLI uses 'nessuscli scan start' [OK]

Hint: Nessus CLI commands start with 'nessuscli' [OK]

Common Mistakes:

• Mixing OpenVAS commands with Nessus
• Using incorrect command order
• Assuming simple flags like '--start-scan' work

3. Consider this simplified output snippet from an OpenVAS scan report:

Host: 192.168.1.10
Vulnerabilities found: 3
 - CVE-2021-1234: High
 - CVE-2020-5678: Medium
 - CVE-2019-0001: Low

What does this output tell you?

medium

A. The scan failed to complete on the host

B. The scan found no vulnerabilities on the host

C. The host is fully secure with no risks

D. The host has three security issues with different severity levels

Solution

1. Step 1: Read the scan report details

   The report lists three vulnerabilities found on the host with severity levels High, Medium, and Low.

2. Step 2: Interpret the meaning of vulnerabilities found

   Since vulnerabilities are listed, the host has security issues. It is not fully secure or failed scan.

3. Final Answer:

   The host has three security issues with different severity levels -> Option D

4. Quick Check:

   Vulnerabilities listed = security issues found [OK]

Hint: Vulnerabilities listed means issues found [OK]

Common Mistakes:

• Ignoring the vulnerability count
• Assuming no vulnerabilities means secure
• Confusing scan failure with vulnerabilities

4. You run an OpenVAS scan but get no results even though you know vulnerabilities exist. Which of these is the most likely cause?

medium

A. The target system is offline

B. OpenVAS does not detect vulnerabilities

C. The scan was run without proper credentials or permissions

D. The scan tool is outdated but still shows results

Solution

1. Step 1: Analyze why no results appear despite known vulnerabilities

   Without proper credentials or permissions, OpenVAS cannot access detailed info to find vulnerabilities.

2. Step 2: Evaluate other options

   OpenVAS does not detect vulnerabilities is false; OpenVAS detects vulnerabilities. The target system is offline would cause scan failure, not empty results. The scan tool is outdated but still shows results contradicts showing results.

3. Final Answer:

   The scan was run without proper credentials or permissions -> Option C

4. Quick Check:

   Missing credentials = no vulnerability data [OK]

Hint: No results often mean missing permissions [OK]

Common Mistakes:

• Assuming OpenVAS never detects vulnerabilities
• Confusing offline system with empty results
• Ignoring credential requirements

5. You want to schedule regular vulnerability scans on your network using Nessus. Which approach best ensures continuous security monitoring?

hard

A. Set up automated scheduled scans with email alerts for new vulnerabilities

B. Run manual scans only when a security breach is suspected

C. Disable scans to avoid network slowdowns

D. Scan only once a year during audits

Solution

1. Step 1: Understand best practices for vulnerability scanning

   Regular automated scans with alerts help detect new issues early and maintain security.

2. Step 2: Compare options for continuous monitoring

   Set up automated scheduled scans with email alerts for new vulnerabilities supports continuous monitoring. Options B, C, and D delay detection or reduce security.

3. Final Answer:

   Set up automated scheduled scans with email alerts for new vulnerabilities -> Option A

4. Quick Check:

   Automated scheduled scans = continuous security [OK]

Hint: Automate scans with alerts for best security [OK]

Common Mistakes:

• Waiting for breaches before scanning
• Disabling scans to save resources
• Scanning only during audits