Wireless network security remains one of the most pressing issues in the IT field, especially when it comes to testing the resilience of home infrastructure to external influences. Using specialized distributions such as Kali Linux, allows administrators and enthusiasts to conduct in-depth vulnerability analysis without resorting to illegal hacking methods. In 2021, this toolkit underwent significant updates, including new versions of drivers and utilities for more effective testing.
It's important to understand that any analysis of someone else's network without the owner's written permission is illegal. This article is for educational purposes only and is intended to help you strengthen your own security. Wi-Fi routerWe'll explore legal testing methods that can help identify configuration weaknesses and prevent potential malicious attacks.
Modern encryption standards are constantly improving, but older devices may still be vulnerable. Understanding how security protocols work is essential for anyone who wants to ensure reliable data protection. Let's explore the tools the current version of the distribution offers for this purpose.
Preparing the environment and hardware
The first step in the security audit process is to properly prepare the workstation. You will need a computer with an operating system installed. Kali Linux, which can run in Live USB mode or be installed on a hard drive. The key element here is a wireless adapter that supports monitoring and packet injection modes.
Not all Wi-Fi cards are capable of operating in the required mode. Most modules built into laptops have driver limitations. For successful testing, it is recommended to use external USB adapters with chipsets. Atheros AR9271 or Ralink RT3070These devices are guaranteed to support the necessary functions for professional analysis.
After connecting the equipment, you need to make sure the system recognizes the device and the drivers are loaded correctly. You can check this in the terminal using the command lsusb, which will display a list of all connected USB devices. If the adapter appears in the list, you can proceed to configuring the interface.
⚠️ Warning: Using monitoring modes may temporarily interrupt your regular Wi-Fi internet connection. It is recommended to have an alternative connection, such as a wired Ethernet connection.
Setting the wireless interface to monitoring mode
The Wi-Fi adapter's default operating mode is called "Managed," in which it connects to the access point as a client. To analyze traffic, you need to switch the interface to "Managed" mode. MonitorThis allows the card to capture all data packets passing through the air on a specific frequency, regardless of whether they are addressed to your device or not.
In the distribution Kali Linux 2021 A utility is often used to manage wireless interfaces airmon-ngBefore starting monitoring mode, it is recommended to close processes that may conflict with the network card, such as connection managers. This is done with the command airmon-ng check kill, which will automatically terminate interfering services.
To activate the monitoring mode, run the command airmon-ng start wlan0, Where wlan0 — the name of your interface. Once successfully executed, the system will create a new virtual interface, usually called wlan0monThis is the interface that further scanning tools will work with.
☑️ Checking adapter readiness
It's worth noting that in some cases, especially with newer Linux kernels, the process may differ. Always consult the official documentation for your specific adapter, as manufacturers may change firmware and driver requirements.
Analysis of the surrounding ether and search for targets
After setting up the interface, the exploration phase begins. The tool airodump-ng is the de facto standard for scanning wireless space. It displays a list of all available networks within range, showing their SSID (network name), channel, signal strength, and encryption method used.
Scanning is started with the command airodump-ng wlan0monA table with data that updates in real time will appear on the screen. Pay attention to the column ENC, which indicates the encryption type: WPA2 is the current standard, while WEP is considered obsolete and highly vulnerable.
For a more detailed study of a specific network, you can filter the output by specifying the target channel and BSSID (the router's MAC address). This allows you to focus on analyzing a single access point, ignoring noise from neighboring networks. The collected information will be saved to a file for later analysis.
| Parameter | Description | Importance for audit |
|---|---|---|
| BSSID | MAC address of the access point | High (target ID) |
| PWR | Signal strength | Average (determines the quality of the connection) |
| ENC | Encryption type (WPA2/WPA3) | Critical (determines the attack method) |
| CH | Broadcast channel | High (necessary for fixation) |
Testing the strength of passwords and handshakes
The primary method for verifying password strength in WPA2 networks is capturing a four-way handshake. This is an authentication process that occurs each time a client connects to the network. To successfully capture a handshake, you must wait for the device to connect or force the client to disconnect to force a reconnection.
Tool aireplay-ng allows you to send deauthentication packets (deauth). This is a legitimate testing method that breaks the connection between the client and the router. The command looks like this: aireplay-ng --deauth 10 -a [BSSID] wlan0monAfter that airodump-ng will record the reconnection process and save the password hash.
The resulting file contains a hashed version of the password. While it's useless for access on its own, it allows you to test the password's strength using brute-force or dictionary attacks. Utilities are used for this. hashcat or john, which compare a hash to millions of combinations.
⚠️ Warning: Excessive use of deauthentication packets may constitute a Denial of Service (DoS) attack. Only perform tests on your own hardware and for a short period of time.
Why are strong passwords important?
Simple passwords like "12345678" or "password" are instantly cracked. Using a combination of letters, numbers, and symbols longer than 12 characters makes brute-force attacks virtually impossible, even for powerful systems.
WPS Protocol Vulnerabilities and Protection Methods
Protocol WPS (Wi-Fi Protected Setup) was created to simplify device connection, but it has become one of the biggest security holes. It allows connecting to a network using an 8-digit PIN. Due to the flawed design of the protocol, the number of possible combinations is drastically reduced, making it possible to brute-force the code in a matter of hours.
In the arsenal Kali Linux there is a tool reaver or its more modern version bullyThese utilities automatically attempt to guess the PIN code. If WPS is enabled on the router and no attempt limits are set, the network can be compromised even with a complex master password.
For security, we recommend completely disabling the WPS function in your router settings. This won't affect your internet speed, but it will close one of the most dangerous vulnerabilities. You can check for the vulnerability using this utility. wpscan (not to be confused with the WordPress scanner) or wash, included in the reaver package.
Owners of older routers should be especially vigilant. Low-end equipment manufacturers often fail to release firmware updates, leaving their devices permanently vulnerable. In such cases, the only solution is to replace the equipment with more modern ones.
Modern encryption standards and WPA3
With the advent of the standard WPA3 Wireless network security has reached a new level. This protocol uses the SAE (Simultaneous Authentication of Equals) method, which protects against brute-force attacks even when weak passwords are used. Unlike WPA2, it doesn't transmit a hash that can be intercepted and cracked offline.
However, vulnerabilities have also been found in WPA3, such as the "Dragonblood" attack. This allows for password complexity to be reduced or a timing attack to be performed. Tools Kali Linux 2021 includes modules to check for these vulnerabilities, allowing administrators to assess the risks.
Upgrading to WPA3 requires support from both the router and all connected devices. Currently, this is the most secure way to secure your home network. If your equipment only supports WPA2, make sure it's using encryption. AES, and not outdated TKIP.
FAQ: Frequently Asked Questions about Wi-Fi Security
Is it possible to hack Wi-Fi from a phone without Kali Linux?
There are many apps that do this, but they either require root access or are scams. A full security audit is only possible with a fully functional adapter and a PC. Mobile operating systems have limited access to Wi-Fi drivers.
Will hiding my SSID prevent my network from being hacked?
No, hiding the network name (SSID) is not a security method. The network still emits signals that are easily detected by professional tools. This only creates the illusion of security and can hinder legitimate users from connecting.
How often should I change my Wi-Fi password?
If you use a strong, unique password and WPA2/WPA3 encryption, frequent password changes are not necessary. Password changes should be made if you suspect a compromise, if employees leave, or if the password has been shared with third parties.
Is guest mode dangerous for the main network?
Guest mode, on the other hand, enhances security. It isolates guests from your main local network, where computers with data, printers, and smart home devices are located. Guests only have internet access.