Vulnerabilities in Wireless Networks
Overview
Teaching: 50 min
Exercises: 0 minQuestions
Key question (FIXME)
Objectives
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Vulnerabilities of Wireless Networks: Man-in-the-Middle Attacks and Sniffing
Wireless networks are inherently more vulnerable than wired networks because they rely on radio signals, which can be intercepted, manipulated, or disrupted by attackers. Some of the most common wireless security threats include Man-in-the-Middle (MITM) attacks and Packet Sniffing, both of which can compromise sensitive data and network integrity.
1. Man-in-the-Middle (MITM) Attacks
1.1 What is a MITM Attack?
A Man-in-the-Middle (MITM) attack occurs when an attacker intercepts and possibly alters communication between two parties without their knowledge. The attacker positions themselves between the sender and receiver to eavesdrop, steal data, or inject malicious content.
Example:
- Attacker impersonates a trusted WiFi access point in a coffee shop, tricking users into connecting.
- The attacker monitors all traffic (logins, emails, messages, credit card details).
- If connections are unencrypted, the attacker can steal or alter the data in transit.
1.2 Types of MITM Attacks in Wireless Networks
| Attack Type | How It Works | Impact |
|---|---|---|
| Rogue Access Point (Evil Twin Attack) | Attacker sets up a fake WiFi hotspot with the same SSID as a legitimate network | Users unknowingly connect and expose sensitive data |
| WiFi Deauthentication Attack | Attacker forces users to disconnect from a real WiFi and reconnect to a rogue AP | Attackers intercept login credentials and communications |
| Session Hijacking | Attacker steals active session cookies to impersonate a user | Account takeover (email, banking, social media) |
| DNS Spoofing | Redirects users to a fake website that mimics a legitimate one | Phishing and malware injection |
| SSL Stripping | Downgrades HTTPS connections to HTTP to remove encryption | Exposes passwords, credit card info, and personal data |
🔴 High-Risk Wireless Networks:
- Public WiFi (airports, hotels, coffee shops)
- Open or weakly encrypted WiFi (WEP, WPA1)
- IoT devices with weak authentication
1.3 MITM Attack Prevention Strategies
✅ Use Encrypted Connections
- Always use HTTPS (TLS 1.3) websites.
- Enable VPNs (Virtual Private Networks) on public WiFi.
- Use end-to-end encrypted messaging apps (Signal, WhatsApp).
✅ Secure WiFi Configurations
- Use WPA3 encryption for wireless networks.
- Disable SSID broadcasting and use MAC address filtering.
- Enable network segmentation to separate IoT from critical systems.
✅ Use Strong Authentication
- Implement Multi-Factor Authentication (MFA) to prevent session hijacking.
- Use certificates and public key authentication for enterprise networks.
✅ Monitor Network Traffic
- Deploy Intrusion Detection Systems (IDS) & Intrusion Prevention Systems (IPS).
- Use AI-driven anomaly detection for unusual network behavior.
2. Packet Sniffing Attacks
2.1 What is Packet Sniffing?
Packet sniffing is the process of capturing and analyzing wireless network traffic to extract sensitive information such as passwords, emails, or financial transactions.
Example:
- An attacker with a WiFi adapter in monitor mode can capture packets in an open WiFi network.
- If the data is unencrypted, they can extract sensitive information such as login credentials, API keys, or credit card numbers.
2.2 Types of Packet Sniffing Attacks
| Attack Type | How It Works | Impact |
|---|---|---|
| Passive Sniffing | Attacker quietly monitors and captures data packets without interfering | Silent data theft, credential harvesting |
| Active Sniffing | Attacker injects packets into the network to manipulate or redirect traffic | MITM, session hijacking |
| WiFi Eavesdropping | Attackers use sniffing tools like Wireshark to capture unencrypted WiFi traffic | Leaks passwords, emails, and financial transactions |
| ARP Spoofing (Address Resolution Protocol Attack) | Attacker associates their MAC address with a target’s IP to intercept traffic | Network takeover, MITM attacks |
| DNS Snooping | Monitoring DNS requests to track user activity and redirect traffic | Phishing, malware injection |
🔴 Common Tools Used for Packet Sniffing:
- Wireshark (network protocol analyzer)
- tcpdump (command-line packet capture tool)
- Bettercap (MITM framework)
- Aircrack-ng (WiFi sniffing and cracking suite)
2.3 Preventing Packet Sniffing Attacks
✅ Encrypt Wireless Traffic
- Use WPA3 or WPA2-AES encryption for WiFi networks.
- Enable end-to-end encryption (TLS 1.3, VPNs, SSH).
- Use encrypted DNS (DNS-over-HTTPS, DNS-over-TLS) to prevent snooping.
✅ Secure WiFi Connections
- Avoid connecting to public/open WiFi networks.
- Use personal mobile hotspots instead of public WiFi.
- If using public WiFi, enable a VPN to encrypt traffic.
✅ Monitor Network Traffic for Anomalies
- Use network monitoring tools (Zeek, Snort, Suricata) to detect suspicious activity.
- Deploy firewalls and IDS/IPS to prevent unauthorized packet capture.
✅ Use Secure Authentication Methods
- Use certificate-based authentication instead of passwords.
- Implement Zero-Trust security models for access control.
3. Comparing MITM Attacks & Sniffing
| Attack Type | Method | Target | Impact |
|---|---|---|---|
| MITM Attack | Intercepts and manipulates communication | Encrypted or unencrypted wireless networks | Data theft, session hijacking, phishing |
| Packet Sniffing | Captures unencrypted data packets | Open WiFi, weak encryption (WEP, WPA1) | Credential theft, monitoring, data exfiltration |
🔴 Key Difference:
- MITM attacks modify data in transit, while packet sniffing passively captures data.
- MITM attacks often involve deception (spoofing, phishing, rogue APs), while sniffing relies on listening to existing transmissions.
✅ Best Defense Strategy: Use strong encryption (WPA3, VPNs, TLS 1.3) and secure authentication methods to protect against both MITM and sniffing attacks.
4. Conclusion
Wireless networks are highly vulnerable to MITM attacks and packet sniffing, making security measures critical. Attackers exploit open WiFi, weak encryption, and insecure authentication to steal credentials, manipulate traffic, and compromise data integrity.
🔐 Best Practices for Wireless Security
✔ Use WPA3 encryption for WiFi security.
✔ Avoid public WiFi or use VPNs when necessary.
✔ Enable Multi-Factor Authentication (MFA) to protect against account takeovers.
✔ Use HTTPS & TLS 1.3 to encrypt sensitive data.
✔ Monitor networks for anomalies with IDS/IPS.
Key Points
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