Do you know the differences between WPS and WPA attacks? You should if you plan to take the Security+ exam. For example, can you answer this question?
Q. A war driver is capturing traffic from a wireless network. When an authorized client connects, the attacker is able to implement a brute force attack to discover the encryption key. What type of attack did this war driver use?
A. WPS attack
B. IV attack
C. Packet injection
D. WPA cracking
More, do you know why the correct answer is correct and the incorrect answers are incorrect? Answer and explanation at end of this post.
The 601 Version of the Study Guide
The CompTIA Security+: Get Certified Get Ahead: SY0-601 Study GuideEach of the eleven chapters presents topics in an easy to understand manner and includes real-world examples of security principles in action.
You’ll understand the important and relevant security topics for the Security+ exam, without being overloaded with unnecessary details. Additionally, each chapter includes a comprehensive review section to help you focus on what’s important.
Over 300 realistic practice test questions with in-depth explanations will help you test your comprehension and readiness for the exam. The book includes:
- A 75 question pre-test
- A 75 question post-test
- Practice test questions at the end of every chapter.
Each practice test question includes a detailed explanation to help you understand the content and the reasoning behind the question. You’ll be ready to take and pass the exam the first time you take it.
If you plan to pursue any of the advanced security certifications, this guide will also help you lay a solid foundation of security knowledge. Learn this material, and you’ll be a step ahead for other exams. This SY0-601 study guide is for any IT or security professional interested in advancing in their field, and a must-read for anyone striving to master the basics of IT security.
WPA Cracking Attacks
Unfortunately, WPA (Wi-Fi Protected Access) is susceptible to password-cracking attacks, especially when the network is using a weak PSK or passphrase. A WPA cracking attack involves three steps:
1. Use a wireless sniffer or protocol analyzer to capture wireless packets. Sniffing this way is similar to how attackers sniff wired networks to eavesdrop and capture information sent across a network.
2. Wait for a wireless client to authenticate. WPA wireless clients authenticate with WAPs using a four-way handshake where they exchange information. Essentially, the client needs to prove to the WAP that it knows the passphrase. However, the client doesn’t send the passphrase in cleartext. Instead, the four-way handshake allows the client to encrypt the passphrase in such a way that the WAP can decrypt it and verify that the client has the correct passphrase.
3. Use a brute force attack. Once attackers have the encrypted passphrase from the captured four-way handshake, they can launch an offline brute force attack. Automated tools such as Aircrack-ng compare the encrypted password in the capture against passwords in one or more password files. When successful, it gives the attacker the actual passphrase used by the WLAN.
A key here is that the attacker must capture the four-way handshake. This only occurs when a user tries to authenticate. If no one is active on the network, this attack won’t work. However, if a user is active, the attacker can use a different attack, such as a jamming attack, to disconnect the user and force the user’s system to authenticate again.
Remember this
In WPA cracking attacks, attackers capture traffic with a wireless sniffer waiting for an authorized client to connect, so that they can capture the four-way authentication handshake information. They then use a brute force attack to discover the passphrase.
WPS Attacks
Wi-Fi Protected Setup (WPS) allows users to configure a wireless network without typing in the passphrase. Instead, users can configure devices by pressing buttons or by entering a short personal identification number (PIN).
For example, a user can configure a new wireless device by pressing a button on the WAP and on the wireless device. It will automatically configure the device within about 30 seconds with no other actions needed. These buttons can be physical buttons on the devices, or virtual buttons that the user clicks via an application or web page. When using the PIN method, users first identify the eight-digit PIN on the WAP and then enter the PIN on the new wireless device.
Unfortunately, WPS is susceptible to brute force attacks. A WPS brute force attack keeps trying different PINs until it succeeds. Reaver is an open source tool freely available that allows attackers to discover the PIN within 10 hours, and often much quicker. Once it discovers the PIN, it can then discover the passphrase in both WPA and WPA2 wireless networks.
Security experts recommend disabling WPS on all devices. However, not all devices include the capability to turn off WPS. Worse, many WAP interfaces include configuration settings that appear to turn off WPS—making users think it’s disabled when it’s still operational and vulnerable to attacks. Several testers reported that they were unable to disable WPS on each Linksys and Cisco Valet WAPs they tested. Some vendors have released firmware updates to address this, but updates are not available for all devices.
Q. A war driver is capturing traffic from a wireless network. When an authorized client connects, the attacker is able to implement a brute force attack to discover the encryption key. What type of attack did this war driver use?
A. WPS attack
B. IV attack
C. Packet injection
D. WPA cracking
Answer is D. A Wi-Fi Protected Access (WPA) cracking attack captures traffic and then performs an offline brute force attack to discover the encryption key.
Wi-Fi Protected Setup (WPS) attacks also use a brute force attack, but do not need to wait for an authorized client to connect.
Initialization vector (IV) attacks often use packet injection techniques to generate more traffic in Wired Equivalent Privacy (WEP) attacks.
