DevLink - WiFu: You think your wireless is secure?
You think your Wifi is Safe? Rob Gillen @argodev
Don’t Be StupidThe following presentation describesreal attacks on real systems. Pleasenote that most of the attacksdescribed would be considered ILLEGALif attempted on systems that you donot have explicit permission to testand attack. I assume no responsibilityfor any actions you perform based onthe content of this presentation orsubsequent conversations. Pleaseremember this basic guideline: Withknowledge comes responsibility.
DisclaimerThe content of this presentationrepresents my personal views andthoughts at the present time. Thiscontent is not endorsed by, orrepresentative in any way of myemployer nor is it intended to be aview into my work or a reflection onthe type of work that I or my groupperforms. It is simply a hobby andpersonal interest and should beconsidered as such.
Credits• Almost nothing in this presentation is original to me.• BackTrack 5 Wireless Penetration Testing Beginners Guide (PACKT Publishing)• HAK5, Darren Kitchen, et. al.• The guy sitting at Starbucks last night• The Internet (et. al.)
Overview• Pre-Requisite Knowledge• Various Security Approaches• Tools and Attacks
Required Gear• Network Adapter that supports “Monitor” mode. – Equivalent to promiscuous mode on a normal NIC• Windows, MAC, or Linux – Linux tools tend to be more readily available• Comfort at the command line
Today’s Lab• Host Machine: – Laptop, Windows 7, hard-wired to AP – presentation, AP configuration• Attacker: – VM, BackTrack 5 SR1, Alfa AWUS036H• Victim: – VM, Mint 13, Netgear USB WiFi Nic• Access Point: – Linksys WRT310Nv1
Wireless Packet Frames• Management Frames • Control Frames – Authentication – Request to Send – De-authentication (RTS) – Association Request – Clear to Send (CTS) – Association Response – Acknowledgment (AWK) – Re-association • Data Frames Request – Re-association Response – Disassociation – Beacon – Probe Request – Probe Response
Packet Sniffing• Determine the channel of the network we are interested in – required for sniffing data packets – airodump-ng• iwconfig mon0 channel 1
Packet Injection• aireplay-ng – Inject packets onto a specific wireless network without specific association to that network – Can target specific channels, mask MAC addresses, etc. – Does not require association
Wireless Channels• 802.11 a,b,g,n slice up their spectrum into channels• Channels are padded by whitespace• 802.11b on 2.4GHz uses 22MHz wide channels• 5 MHz unused spectrum buffers each channel
Channels and Overlap • Channel 1: Centered at 2.412 GHz begins at 2.400 and ends at 2.422 GHz • Channel 2: Centered at 2.417 begins 5MHz past Channel 1’s beginning • Channel 3: Centered at 2.422 GHz begins 5MHz past Channel 2’s beginning • Channels 1, 6, 11, and 14 are discreteImage Source: Wikipedia http://en.wikipedia.org/wiki/File:2.4_GHz_Wi-Fi_channels_(802.11b,g_WLAN).svg
Regulatory Issues• Available Channels – US: 1-11 – Everywhere Else: 1-13 – Japan: 1-14• Radio Power Levels – iw reg set US (up to 20) – iw reg set BO (up to 30)
De-authentication Packets • Polite way to disconnect a client from the network • Gives everyone a chance to free memory • Hackers best friendContent for this slide taken from WiFi workshop, NoiseBridge, presented by Darren Kitchenhttp://hak5.org/episodes/hak5-1122
DEMO: Hidden SSID• Show packet capture with the SSID• Hide SSID• Prove it is now hidden• Solve for X – Passive (wait for valid client) – wireshark filter – Use aireplay-ng to send deauth packet to force the discovery• Probe Request/Probe Response packets
DEMO: WEP Encryption• Capture data packets (ARP) from a known/trusted client (airodump-ng)• Replay them/re-inject between 10- 100,000 times (aireplay-ng)• Crack them (aircrack-ng)• Guaranteed crack