Network Threats and Vulnerabilities

📘 Network Threats and Vulnerabilities — Exam Notes (Network Security)

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🔐 1. Definition

🔹 Network Threat

A network threat is any potential danger or attack that can harm a network by stealing data, disrupting services, or gaining unauthorized access.

🔹 Vulnerability

A vulnerability is a weakness or flaw in a system, network, or application that can be exploited by attackers.

👉 Simple idea:

• Threat = Possible attack
• Vulnerability = Weak point used for attack

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🎯 2. Relationship Between Threat and Vulnerability

👉 A threat becomes dangerous only when a vulnerability exists.

Example:

• Threat: Hacker trying to enter system
• Vulnerability: Weak password
• Result: Unauthorized access

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⚠️ 3. Types of Network Threats

🔸 1. Passive Threats

• Monitor data without changing it.
• Hard to detect.

Examples:

• Eavesdropping
• Traffic analysis

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🔸 2. Active Threats

• Modify, disrupt, or damage data.

Examples:

• Data modification
• Denial of Service (DoS)
• Man-in-the-Middle (MITM)

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🔸 3. Insider Threats

• Attacks from authorized users.

Examples:

• Employee stealing data
• Misuse of privileges

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🔸 4. External Threats

• Attacks from outside the organization.

Examples:

• Hackers
• Malware attacks

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🦠 4. Common Network Attacks

🔹 Malware

Malicious software designed to harm systems:

• Virus → attaches to files
• Worm → spreads automatically
• Trojan → appears safe but harmful

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🔹 Phishing

• Fake emails/websites to steal sensitive data.

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🔹 DoS / DDoS Attack

• Floods network with traffic → makes it unavailable.

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🔹 Spoofing

• Fake identity (IP, email, website).

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🔹 Man-in-the-Middle (MITM)

• Attacker secretly intercepts communication.

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🔹 Password Attacks

• Guessing or stealing passwords:

  • Brute force
  • Dictionary attack

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🧱 5. Types of Vulnerabilities

🔸 Software Vulnerabilities

• Bugs or flaws in software.
• Example: Unpatched systems.

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🔸 Network Vulnerabilities

• Weak network configurations.
• Example: Open ports, weak firewall rules.

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🔸 Human Vulnerabilities

• Mistakes by users.

• Example:

  • Weak passwords
  • Falling for phishing

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🔸 Physical Vulnerabilities

• Physical access to devices.
• Example: Unlocked server rooms.

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🔍 6. Vulnerability Lifecycle

1. Discovery → Weakness identified
2. Exposure → Known publicly
3. Exploitation → Attacker uses it
4. Patch/Fix → Security update applied

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🛡️ 7. Risk Concept

🔹 Risk Formula

Risk = Threat × Vulnerability

👉 Higher vulnerability = higher risk

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🔑 8. Methods to Reduce Threats & Vulnerabilities

🔸 Technical Controls

• Firewalls
• Antivirus
• Encryption
• IDS/IPS

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🔸 Administrative Controls

• Security policies
• User training
• Access control

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🔸 Physical Controls

• CCTV
• Locks
• Security guards

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🖼️ 9. Diagram Descriptions

📌 Threat–Vulnerability Relationship Diagram

• Show:

  • Threat → Vulnerability → Attack → Damage

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📌 Risk Model Diagram

• Triangle showing:

  • Threat
  • Vulnerability
  • Impact

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📌 Attack Flow Diagram

• Attacker → Exploit → System → Data breach

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🧾 10. Real-Life Examples

• 📧 Phishing email stealing bank login
• 🏢 Company server hacked due to outdated software
• 🔓 Public Wi-Fi leading to MITM attack
• 🔑 Weak passwords leading to account hacking

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📝 Likely Exam Questions

1. Define network threat and vulnerability with examples.
2. Differentiate between threat and vulnerability.
3. Explain types of network threats.
4. Describe common network attacks.
5. What are software and human vulnerabilities?
6. Explain DoS and MITM attacks.
7. What is risk in network security? Explain formula.
8. Describe vulnerability lifecycle.
9. How can threats be minimized?
10. Write short notes on:

• Phishing
• Malware
• Spoofing

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📌 Quick Summary / Conclusion

• Threats are dangers; vulnerabilities are weaknesses.
• Attacks happen when threats exploit vulnerabilities.
• Common threats include malware, phishing, and DoS.
• Vulnerabilities can be technical, human, or physical.
• Risk depends on both threats and vulnerabilities.
• Security measures help reduce risks and protect systems.

👉 In short: Understanding threats and vulnerabilities is essential to prevent cyber attacks and secure networks effectively.

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