Wireless networks, like those found in public places such as airports and restaurants, are easily accessible within the router's range, which also makes them susceptible to attacks. In this tutorial, we'll explore common techniques for exploiting vulnerabilities in wireless network security and discuss countermeasures to safeguard against these attacks.
Topics covered include:
- Understanding wireless networks
- Accessing wireless networks
- Wireless network authentication methods (WEP & WPA)
- Techniques for cracking wireless networks
- Strategies for securing wireless networks, including hacking activity on password cracking.
What is a wireless network?
A wireless network utilizes radio waves to establish connections between computers and various devices. This communication occurs at the physical layer (Layer 1) of the OSI model, facilitating seamless interactions among devices.
How to access a wireless network?
To access a wireless network, you'll require a device with wireless capability, such as a laptop, tablet, or smartphone. Ensure you're within the transmission range of a wireless access point. Most devices will detect available networks; if unsecured, simply click "connect." For secured networks, you'll need the password for access.
Wireless Network Authentication
Given the accessibility of wireless networks to anyone with a compatible device, most networks implement password protection. Here, we'll explore commonly used authentication techniques.
WEP (Wired Equivalent Privacy)
WPA Authentication
- Open System Authentication (OSA): Grants access based on configured access policies.
- Shared Key Authentication (SKA): Involves sending an encrypted challenge to requesting stations, which, upon correct encryption and response, gain access.
WEP Weaknesses
WEP suffers from significant design flaws and vulnerabilities:- Packet integrity checks via CRC32 can be compromised, allowing unauthorized access.
- RC4 encryption algorithm used by WEP, with its short key lengths, facilitates easy cracking.
- Weaknesses in initial value combinations render encryption insufficient.
- Vulnerability to dictionary attacks due to password-based authentication.
- Poor key management, especially in large networks, lacks a centralized system.
- The reuse of initial values further compromises security, leading to WEP's deprecation in favor of WPA.
WPA (Wi-fi Protected Access)
WPA Weaknesses
Despite improvements, WPA still has vulnerabilities:- Collision avoidance implementation is susceptible to breakage, making it prone to denial of service attacks.
- Pre-shared keys using passphrases are vulnerable to dictionary attacks if weak.
Cracking Wireless Networks
WEP Cracking
Cracking wireless networks involves exploiting security weaknesses to gain unauthorized access. WEP cracking specifically targets networks utilizing WEP for security. There are two main types:- Passive cracking: This method remains undetectable until the WEP security is breached, making it challenging to identify.
- Active cracking: This approach increases network traffic load, making it easier to detect but more effective than passive cracking.
WEP Cracking Tools
- Aircrack: A network sniffer and WEP cracker.
- WEPCrack: An open-source program implementing the FMS attack.
- Kismet: A tool for detecting wireless networks, packet sniffing, and intrusion detection.
- WebDecrypt: Utilizes active dictionary attacks and packet filters.
WPA Cracking
WPA employs a 256-bit pre-shared key or passphrase for authentication. Short passphrases are susceptible to dictionary attacks and other cracking methods. Tools for WPA cracking include:
- CowPatty: Used for brute force attacks on pre-shared keys (PSK).
- Cain & Abel: Decodes capture files from sniffing programs like Wireshark, potentially containing WPA-PSK encoded frames.
General Attack Types
- Sniffing: Intercepting and decoding transmitted packets, often done with tools like Cain & Abel.
- Man-in-the-Middle (MITM) Attack: Eavesdropping on a network to capture sensitive information.
- Denial of Service (DoS) Attack: Intends to deny legitimate users access to network resources, with tools like FataJack facilitating such attacks.
