📘 Network Threats and Vulnerabilities — Exam Notes (Network Security)
🔐 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
🎯 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
⚠️ 3. Types of Network Threats
🔸 1. Passive Threats
- Monitor data without changing it.
- Hard to detect.
Examples:
- Eavesdropping
- Traffic analysis
🔸 2. Active Threats
- Modify, disrupt, or damage data.
Examples:
- Data modification
- Denial of Service (DoS)
- Man-in-the-Middle (MITM)
🔸 3. Insider Threats
- Attacks from authorized users.
Examples:
- Employee stealing data
- Misuse of privileges
🔸 4. External Threats
- Attacks from outside the organization.
Examples:
🦠 4. Common Network Attacks
🔹 Malware
Malicious software designed to harm systems:
- Virus → attaches to files
- Worm → spreads automatically
- Trojan → appears safe but harmful
🔹 Phishing
- Fake emails/websites to steal sensitive data.
🔹 DoS / DDoS Attack
- Floods network with traffic → makes it unavailable.
🔹 Spoofing
- Fake identity (IP, email, website).
🔹 Man-in-the-Middle (MITM)
- Attacker secretly intercepts communication.
🔹 Password Attacks
🧱 5. Types of Vulnerabilities
🔸 Software Vulnerabilities
- Bugs or flaws in software.
- Example: Unpatched systems.
🔸 Network Vulnerabilities
- Weak network configurations.
- Example: Open ports, weak firewall rules.
🔸 Human Vulnerabilities
-
Mistakes by users.
-
Example:
- Weak passwords
- Falling for phishing
🔸 Physical Vulnerabilities
- Physical access to devices.
- Example: Unlocked server rooms.
🔍 6. Vulnerability Lifecycle
- Discovery → Weakness identified
- Exposure → Known publicly
- Exploitation → Attacker uses it
- Patch/Fix → Security update applied
🛡️ 7. Risk Concept
🔹 Risk Formula
Risk = Threat × Vulnerability
👉 Higher vulnerability = higher risk
🔑 8. Methods to Reduce Threats & Vulnerabilities
🔸 Technical Controls
- Firewalls
- Antivirus
- Encryption
- IDS/IPS
🔸 Administrative Controls
- Security policies
- User training
- Access control
🔸 Physical Controls
- CCTV
- Locks
- Security guards
🖼️ 9. Diagram Descriptions
📌 Threat–Vulnerability Relationship Diagram
-
Show:
- Threat → Vulnerability → Attack → Damage
📌 Risk Model Diagram
-
Triangle showing:
- Threat
- Vulnerability
- Impact
📌 Attack Flow Diagram
- Attacker → Exploit → System → Data breach
🧾 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
📝 Likely Exam Questions
- Define network threat and vulnerability with examples.
- Differentiate between threat and vulnerability.
- Explain types of network threats.
- Describe common network attacks.
- What are software and human vulnerabilities?
- Explain DoS and MITM attacks.
- What is risk in network security? Explain formula.
- Describe vulnerability lifecycle.
- How can threats be minimized?
- Write short notes on:
- Phishing
- Malware
- Spoofing
📌 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.