Wi-fi Hacking

WI-FI SECURITYA gentle introduction to Hacking Wi-Fi

Thursday, February 25, 2010

PRESENTED BY

Paul Gillingwater, CISSP, CISMAdjunct Professor of Computer ScienceWebster University Vienna

http://security-risk.blogspot.com

Working in IT Security 20+ years


http://security-risk.bogspot.com

http://security-risk.bogspot.com

A BRIEF OVERVIEW

Wi-Fi has been around more than 12 years -- originally, it lacked any form of security

Since 2001, Wireless Encryption Protocol (WEP) has been successfully attacked -- in 2007, it takes no more than 90,000 packets to break keys (due to weaknesses in RC4) -- time to crack less than 1 minute

Since 2004, Wi-Fi Protected Access (WPA & WPA2) were introduced to address WEP’s failure -- but even this is not quite enough for full security


WI-FI HISTORY

Originally offered as IEEE 802.11 in 1997 -- security limited due to export restrictions of certain governments

Implements Wireless LAN access over 2.4 and 5 GHz bands -- former with 3 channels (and shared with Amateur Radio and Cordless Phones), latter with 19

Initial systems 1-2 Mbps, later increased to 11 Mbps with 802.11b, then up to 802.11n with 54-600 Mbps possible (since 2009)


WIRELESS SIGNALS

Any wireless signal can be received by suitable equipment

Key-sharing is fundamental issue -- and the more often a key is used, the easier it is to find it due to mathematics of encryption

In addition to receiving packets, we can also inject packets -- e.g., ARP or de-auth to create traffic


SECURING WI-FI

In my view, only reliable method for securing Wi-Fi is to run a VPN on top (e.g., OpenVPN)

WEP and WPA are easily broken (WPA TKIP cracked in less than 1 minute by Japanese researchers in 2009)

WPA is TKIP -- WPA2 is CCMP, which is better (AES)

WPA2 is probably secure enough for home usage -- but there is still risk of impersonation


TRAFFIC MONITORING

On OSX, from command line (with sudo):/System/Library/PrivateFrameworks/Apple80211.framework/Versions/A/Resources/airport

Specify en1 sniff 1 as parameters to capture packets into /tmp/airportSniffxxxx.cap file

WireShark is free utility for Windows, OSX or Linux that captures and displays packets


HOW WPA WORKS

WPA tried to fix WEP problems, while WPA2 was a new approach to solving security problem

802.1X port access control is key to successful use

This “Enterprise” approach depends on separate RADIUS authentication server -- each new session gets a fresh key, good for a short time

Home networks don’t use RADIUS, so a “Pre Shared Key” (PSK) is used


WPA KEY HANDSHAKE


COW PATTY ATTACK

Where 802.1X not available, PSK may be sniffed from other authenticating stations

KisMac and coWPAtty use dictionary and other attacks to guess the PSK from captured packets

Packet injection can force re-connects to capture

coWPAtty with Rainbow Tables (pre-calculated hashes) can test >18,000 pass-phrases per second


WPA CRACKER

Regular WPA-PSK cracking on “business grade” hardware can take up to two weeks

“WPA Cracker” is a commercial service using cloud-based computing with 400 nodes, which can crack a WPA key in 20 minutes for $34

This is based on 135 million word dictionary attack -- therefore a strong password can defeat this class

Businesses now know the price of security


BOGUS HOTSPOTS

Any computer can also be a Wireless Access Point

Windows 7 has new feature “SoftAP” -- which can be used for Internet Connection Sharing (use Connectify for example -- http://connectify.me/)

However, the “bad guys” can capture all of the packets which pass through their system, even if they connect to you with WEP or WPA

Bad guys can use similar names, e.g., Webster-Wi-Fi


http://connectify.me

http://connectify.me

MAC SPOOFING

Some Access Points allow restriction based on the MAC (Media Access Control) address

This is good basic security, but not reliable -- because attackers can simply sniff for “trusted” address and use that in their own systems

802.1x makes this more difficult for attackers


SUPPRESSING SSID

Most Wi-Fi networks broadcast their network name -- called the SSID

Security may be improved by disabling this feature for a home or business network

However, experienced hackers will simply monitor authorized connections to learn the SSID


MAN IN THE MIDDLE

A MITM attack means intruder pretends to be authorized gateway, but intercepts and can change packets (this was used by Japanese team with TKIP)

Example: Video of “Cain” tool, with packet capture and WEP crackingcracking-wep-with-airpcap-packet-injection-and-cain-and-abel.wmv


BYPASSING AIRPORT WI-FI

Frequent airport travelers know about airport Wi-Fi

Such systems intercept HTTP, redirect to a login page before allowing access (e.g., Boingo Hotspot)

Most airport Wi-Fi allows DNS lookups -- some direct, and some via DNS relay

If port 53 is allowed, then you can run OpenVPN using UDP port 53 to your home system

If DNS relayed, then use DNS tunnel (Linux mostly)


AIRPORT RISKS

“Free” Wi-Fi hotspots in an airport or cafe might belong to a hacker, who is capturing traffic -- including, potentially, user names & passwords

Hackers can also relay HTTPS -- so don’t assume your password is safe at a public Hot Spot

Most hotspots don’t use WEP or WPA -- so most traffic is not encrypted (unless SSH or SSL is used)


WI-FI SECURITY ADVICE

Avoid WEP and WPA/TKIP, use WPA2 or WPA/AES

If using in a business, use 802.1X -- otherwise make sure you have PSK length > 20 characters

Use MAC access control (restrict connecting devices based on their internal address)

Use VPN for truly sensitive information


TJ Maxx is classic example of Wi-Fi vector: resulted in loss of 45 million customer records (Credit Card details)

The weakness was the use of WEP to secure a LAN, which was exploited by the hackers

This breach cost the company $12 million in direct costs, not including the subsequent remedial work and loss of PCI compliance

Average cost of a Data Breach rose to $200 per customer record in 2009, according to Ponemon Institute study -- average total cost rose to $6.75m

COMMERCIAL RISKS


LEGAL ASPECTS

In many countries, hacking other’s Wi-Fi is illegal -- therefore, do any tests using your OWN gear

See NCSL web site for summary of States’ laws

“Unauthorized access” can attract serious prosecutions, fines and criminal charges

Within Webster University, unauthorized Wi-Fi access could be grounds for expulsion


LATEST WI-FI TRENDS

Passive-Aggressive SSIDs now used by some... e.g.:

YOURDOGPOOPSINMYYARD

TURNTHEMUSICDOWN

CAITLINSTOPUSINGOURINTERNET

WECANHEARYOUHAVINGSEX

OBAMAISASOCIALIST


THANK YOU!

Any questions?

Comments?

Discussion....


Date post:	02-Dec-2014
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Wi-fi Hacking

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