Posts tagged wireless security

Sniffing Traffic on Your Home Router or Hub

I’ve always knew it was possible to sniff traffic on your home network but every time I tried, I always ended up sniffing ‘management type packets’ (e.g. arp requests, syns, acks, etc). I’d never really seen any useful information come across the wire so I pretty much wrote off the idea of sniffing.

Recently I had done a little deeper dive related to some work I’m doing in class and discovered some of the things I’d done wrong in the past. So here’s a short post on sniffing traffic on your home network. Take a minute to understand the concepts and be responsible with your sniffing activities. (more…)

Online WPA Crackers

Almost everything, in some sense or another, is vulnerable to brute force. It’s just a matter of how long it takes for something to be brute forced that tends to it’s security. I found it pretty interesting that there are now online WPA crackers that will mount dictionary attacks against captured WPA authentication handshakes: (more…)

The Current State of Wireless Security

This post is a small survey of existing Wi-Fi security protocols pertaining to home and small offices as of Oct. 25th, 2010

WEP – Wired Equivalent Privacy – WEAK

Anyone with the slightest knowledge of wireless security protocols knows that WEP is very insecure. A very inexperienced individual can get the tools and watch a tutorial on how to crack a WEP key in a few hours. WEP seriously has so many problems from a cryptographic point of view.

  • The master key is used within the encryption instead of deriving a key from the master key.
  • Keys can be derived from datagrams.
  • The hashing algorithm it uses for integrity is weak (CRC32)

Do not secure your network with WEP. WEP will be completely out of production by 2014.

WPA – Wi-Fi Protected Access – MODERATE-STRONG

WPA was the interm solution to WEP’s serious weaknesses while WPA2 was developed. One of the important points of WPA is that it derives encryption keys from the master key instead of utilizing the master key in the encryption.

WPA has held it’s ground for some time but it still vulnerable to brute-forcing weak passwords by capturing an authentication handshake.Weaknesses in WPA implementations have been discovered as early as 2008 and are continuing to be discovered into early 2010.

The current vulnerabilities exist in the Temporal Key Integrity Protocol (TKIP) (the enhanced protocol to address WEP vulnerabilities). They allow an attacker to inject a small amount of valid encrypted packets of their choice. When the original vulnerability was discovered, Quality of Service (QoS) needed to be enabled on the access point in order to successfully take advantage of the vulnerabilities. Specifically, having QoS enabled,
allowed one to bypass WPAs replay protection. However, as of early 2010, the QoS requirement for the attack is not required. Because this vulnerability doesn’t expose the key, people are not as concerned about it and it hasn’t warranted much concern. Although the attacks aren’t much of a concerned, I’d suggest if you’re going to use WPA, use WPA-AES, NOT WPA-TKIP. TKIP was officially deprecated from the 802.11 spec as of early 2009. The take home message of WPA as quoted from the Wi-Fi alliance:

Q: Is WPA still secure?
Yes, WPA remains secure. WPA is the major upgrade to Wi-Fi security, applicable to
enterprise and home users. WPA was independently verified to address all of WEP’s
known weaknesses. WPA2 is not being released to address any flaws in WPA.

WPA2 – Wi-Fi Protected Access 2 – STRONG

WPA2 was the final spec that the Wi-Fi Alliance had been working on when WEP vulnerabilities were discovered. Instead of utilizing TKIP for encryption, WPA2 utilizes AES. WPA2 is very similar to WPA-AES with a few minor differences that are negligible to security protection.

Like WPA, WPA2 passwords can also be brute-forced, thus strong and random passwords should be used. Other weaknesses in WPA2 do exist but they can generally be avoid by implementing basic security practices. Due to the deprecation of TKIP and the inherently stronger AES encryption, WPA2 is the recommended wireless security protocol. 

Cracking WEP with the Intel 3945abg

Since I’ve been reading a lot about security in networking, I figured I’d give the well known WEP cracking a try.

Common Misconceptions With Wep Cracking
  1. You need a special card to crack WEP keys.
    • This is not true, with some caveats. Any card that can be switched to “monitor mode” can be used to crack WEP keys. The vast majority of cards can do this or someone has written a custom driver (e.g. Airport Extreme Cards on Macs) to enable it. HOWEVER, and this is a big however; if you want to crack WEP without waiting for days or even weeks, you need a card to supports “packet injection.” This list is much smaller but growing as the hardcore driver writers write custom drivers for them.
    • (more…)

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