Wireless attacks, A to Z

In our buzzword-filled industry, wrapping your arms around wireless attacks and their potential business impacts can be tough. This tip tries to bring order to this chaos by providing a reference list of attacks against 802.11 and 802.1X, categorized by type of threat, and mapped to associated hacker methods and tools.

Wireless Security Lunchtime Learning

 By Lisa Phifer

In our buzzword-filled industry, wrapping your arms around wireless attacks and their potential business impacts can be tough. This tip tries to bring order to this chaos by providing a reference list of attacks against 802.11 and 802.1X, categorized by type of threat, and mapped to associated hacker methods and tools.

Access control attacks

These attacks attempt to penetrate a network by using wireless or evading WLAN access control measures, like AP MAC filters and 802.1X port access controls.

Type of Attack Description Methods and Tools
War Driving Discovering wireless LANs by listening to beacons or sending probe requests, thereby providing launch point for further attacks. DStumbler, KisMAC, MacStumbler, NetStumbler, WaveStumbler, Wellenreiter
Rogue Access Points Installing an unsecured AP inside firewall, creating open backdoor into trusted network. Any hardware or software AP
Ad Hoc Associations Connecting directly to an unsecured station to circumvent AP security or to attack station. Any wireless card or USB adapter
MAC Spoofing Reconfiguring an attacker's MAC address to pose as an authorized AP or station. Bwmachak, changemac.sh, SirMACsAlot, SMAC, Wellenreiter, wicontrol
802.1X RADIUS Cracking Recovering RADIUS secret by brute force from 802.1X access request, for use by evil twin AP. Packet capture tool on LAN or network path between AP and RADIUS server

Confidentiality attacks

These attacks attempt to intercept private information sent over wireless associations, whether sent in the clear or encrypted by 802.11 or higher layer protocols.

Type of Attack Description Methods and Tools
Eavesdropping Capturing and decoding unprotected application traffic to obtain potentially sensitive information. bsd-airtools, Ethereal, Ettercap, Kismet, commercial analyzers
WEP Key Cracking Capturing data to recover a WEP key using brute force or Fluhrer-Mantin-Shamir (FMS) cryptanalysis. Aircrack, AirSnort, chopchop, dwepcrack, WepAttack, WepDecrypt, WepLab
Evil Twin AP Masquerading as an authorized AP by beaconing the WLAN's service set identifier (SSID) to lure users. cqureAP, HermesAP, HostAP, OpenAP, Quetec, WifiBSD
AP Phishing Running a phony portal or Web server on an evil twin AP to "phish" for user logins, credit card numbers. Airsnarf, Hotspotter
Man in the Middle Running traditional man-in-the-middle attack tools on an evil twin AP to intercept TCP sessions or SSL/SSH tunnels. dsniff, Ettercap

Integrity attacks

These attacks send forged control, management or data frames over wireless to mislead the recipient or facilitate another type of attack (e.g., DoS).


Type of Attack Description Methods and Tools
802.11 Frame Injection Crafting and sending forged 802.11 frames. Airpwn, File2air, libradiate, void11, WEPWedgie, wnet dinject/reinject
802.11 Data Replay Capturing 802.11 data frames for later (modified) replay. Capture + Injection Tools
802.11 Data Deletion Jamming an intended receiver to prevent delivery while simultaneously spoofing ACKs for deleted data frames. Jamming + Injection Tools
802.1X EAP Replay Capturing 802.1X Extensible Authentication Protocols (e.g., EAP Identity, Success, Failure) for later replay. Wireless Capture + Injection Tools between station and AP
802.1X RADIUS Replay Capturing RADIUS Access-Accept or Reject messages for later replay. Ethernet Capture + Injection Tools between AP and authentication server

Authentication attacks

Intruders use these attacks to steal legitimate user identities and credentials to access otherwise private networks and services.

Type of Attack Description Methods and Tools
Shared Key Guessing Attempting 802.11 Shared Key Authentication with guessed, vendor default or cracked WEP keys. WEP Cracking Tools
PSK Cracking Recovering a WPA PSK from captured key handshake frames using a dictionary attack tool. coWPAtty, KisMAC, wpa_crack, wpa-psk-bf
Application Login Theft Capturing user credentials (e.g., e-mail address and password) from cleartext application protocols. Ace Password Sniffer, Dsniff, PHoss, WinSniffer
Domain Login Cracking Recovering user credentials (e.g., Windows login and password) by cracking NetBIOS password hashes, using a brute-force or dictionary attack tool. John the Ripper, L0phtCrack, Cain
VPN Login Cracking Recovering user credentials (e.g., PPTP password or IPsec Preshared Secret Key) by running brute-force attacks on VPN authentication protocols. ike_scan and ike_crack (IPsec), anger and THC-pptp-bruter (PPTP)
802.1X Identity Theft Capturing user identities from cleartext 802.1X Identity Response packets. Capture Tools
802.1X Password Guessing Using a captured identity, repeatedly attempting 802.1X authentication to guess the user's password. Password Dictionary
802.1X LEAP Cracking Recovering user credentials from captured 802.1X Lightweight EAP (LEAP) packets using a dictionary attack tool to crack the NT password hash. Anwrap, Asleap, THC-LEAPcracker
802.1X EAP Downgrade Forcing an 802.1X server to offer a weaker type of authentication using forged EAP-Response/Nak packets. File2air, libradiate

Availability attacks

These attacks impede delivery of wireless services to legitimate users, either by denying them access to WLAN resources or by crippling those resources.

Type of Attack Description Methods and Tools
AP Theft Physically removing an AP from a public space. "Five finger discount"
RF Jamming Transmitting at the same frequency as the target WLAN, perhaps at a power that exceeds regulation Equivalent Isotopically Radiated Power (EIRP). RF Jammer, Microwave oven, AP with Alchemy/HyperWRT firmware
Queensland DoS Exploiting the CSMA/CA Clear Channel Assessment (CCA) mechanism to make a channel appear busy. An adapter that supports CW Tx mode, with a low-level utility to invoke continuous transmit
802.11 Beacon Flood Generating thousands of counterfeit 802.11 beacons to make it hard for stations to find a legitimate AP. FakeAP
802.11 Associate / Authenticate Flood Sending forged Authenticates or Associates from random MACs to fill a target AP's association table. Airjack, File2air, Macfld, void11
802.11 TKIP MIC Exploit Generating invalid TKIP data to exceed the target AP's MIC error threshold, suspending WLAN service. File2air, wnet dinject
802.11 Deauthenticate Flood Flooding station(s) with forged Deauthenticates or Disassociates to disconnecting users from an AP. Airjack, Omerta, void11
802.1X EAP-Start Flood Flooding an AP with EAP-Start messages to consume resources or crash the target. QACafe, File2air, libradiate
802.1X EAP-Failure Observing a valid 802.1X EAP exchange, and then sending the station a forged EAP-Failure message. QACafe, File2air, libradiate
802.1X EAP-of-Death Sending a malformed 802.1X EAP Identity response known to cause some APs to crash. QACafe, File2air, libradiate
802.1X EAP Length Attacks Sending EAP type-specific messages with bad length fields to try to crash an AP or RADIUS server. QACafe, File2air, libradiate

Note: Many of these tools can be found in the Auditor Security Collection, a KNOPPIX-based toolkit intended for use during penetration testing and vulnerability assessment.

>> Move to the next tip: Wi-Fi vulnerability assessment checklist

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