🌐 Network Attacks and Session Attacks (Web Engineering)

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📌 1. Definition

🌐 Network Attacks

Network attacks are malicious activities performed over a network to intercept, disrupt, or modify data communication between a client and server.

🔐 Session Attacks

Session attacks are attacks that target a user’s session information (Session ID, cookies, tokens) to hijack or impersonate a legitimate user.

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🌐 2. Network Attacks

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🧠 2.1 Overview

Network attacks target the communication channel between:

• Browser (client)
• Server

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⚠️ 2.2 Types of Network Attacks

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1. 🕵️‍♂️ Man-in-the-Middle (MITM) Attack

📌 Definition

An attacker secretly intercepts communication between two parties.

🔑 How it works:

• Attacker sits between user and server
• Reads or modifies data

📈 Example:

• Stealing login credentials on public Wi-Fi

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2. 📡 Packet Sniffing

📌 Definition

Capturing data packets traveling over a network.

🔑 Example tools:

• Wireshark (used for analysis, but can be misused)

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3. 🔁 Replay Attack

📌 Definition

Attacker re-sends valid data packets to repeat unauthorized actions.

📈 Example:

• Reusing login request packets

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4. 🌊 Denial of Service (DoS/DDoS)

📌 Definition

Overloading a server with traffic to make it unavailable.

🔑 Types:

• DoS → single source
• DDoS → multiple sources

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5. 🧨 DNS Spoofing

📌 Definition

Redirecting users to a fake website by modifying DNS records.

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🔐 3. Session Attacks

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🧠 3.1 Overview

Session attacks target the session management system used in web applications.

👉 Sessions are used to maintain user login state.

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⚠️ 3.2 Types of Session Attacks

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1. 🍪 Session Hijacking

📌 Definition

Stealing a user's session ID to gain unauthorized access.

🔑 Example:

• Attacker logs into victim’s account without password

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2. 🎯 Session Fixation

📌 Definition

Attacker forces a user to use a predefined session ID.

🔑 Process:

1. Attacker sets session ID
2. User logs in using that session
3. Attacker reuses session

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3. 🕵️ Session Sniffing

📌 Definition

Intercepting session cookies using insecure networks.

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4. 💣 Cross-Site Request Forgery (CSRF)

📌 Definition

Forcing a logged-in user to perform unauthorized actions.

📈 Example:

• Transferring money without user consent

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📊 4. Network vs Session Attacks

Feature	Network Attacks 🌐	Session Attacks 🔐
Target	Communication channel	User session data
Focus	Data transfer	Authentication
Example	MITM, DoS	Hijacking, CSRF
Level	Network layer	Application layer

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🧩 5. Attack Flow Diagram

User → Network → Server
      ↘ Attacker intercepts ↙
   (Data / Session Theft)

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🛡️ 6. Prevention Techniques

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🔐 For Network Attacks

✔ Use HTTPS (SSL/TLS encryption) ✔ Firewalls and intrusion detection systems ✔ Secure Wi-Fi networks ✔ Encryption of data packets

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🔐 For Session Attacks

✔ Use strong session IDs ✔ Session expiration (timeout) ✔ Regenerate session ID after login ✔ Use secure cookies (HttpOnly, Secure) ✔ Implement CSRF tokens

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📈 7. Importance in Web Security

• Protects user data
• Prevents unauthorized access
• Ensures secure communication
• Maintains trust in web applications

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⚠️ 8. Important Exam Points

✔ Network attacks target data transmission ✔ Session attacks target user authentication state ✔ HTTPS reduces network attacks ✔ Secure session management reduces session attacks

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❓ 9. Likely Exam Questions

Short Questions

1. Define network attacks.
2. What is session hijacking?
3. What is MITM attack?
4. Define CSRF.
5. Difference between network and session attacks.

Long Questions

6. Explain types of network attacks.
7. Discuss session attacks in web applications.
8. Explain session hijacking and session fixation.
9. Describe prevention techniques for web attacks.
10. Explain network and session attacks with examples.

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📝 10. Summary / Quick Revision

• Network attacks → target communication (MITM, DoS, sniffing)

• Session attacks → target user sessions (hijacking, fixation, CSRF)

• Prevention:

  • HTTPS
  • Secure cookies
  • Session management
  • Encryption

👉 In short: Network attacks break communication security, while session attacks break user authentication security.

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