Wireless Security and Mobile Devices Chapter 12
Objectives • Describe the different wireless systems in use today. • Detail WAP and its security implications. • Identify 802.11’s security issues and possible solutions. • Learn about the different types of wireless attacks. • Examine the elements needed for enterprise wireless deployment. • Examine the security of mobile systems.
Key Terms (1 of 4) • Beacon frames • Bluebugging • Bluejacking • Bluesnarfing • Bluetooth • Bluetooth DoS • Captive portal • Containerization • Custom firmware • Direct-sequence spread spectrum (DSSS) • Disassociation • Extensible Authentication Protocol (EAP) • EAP-FAST • EAP-TLS • EAP-TTLS
Key Terms (2 of 4) • Evil twin • Firmware OTA updates • Geo-tagging • IEEE 802.1X • Infrared (IR) • Initialization vector (IV) • Jailbreaking • Jamming • MAC filtering • MIMO • Mobile device management (MDM) • Multimedia Messaging Service (MMS) • Near field communication (NFC) • Orthogonal frequency division multiplexing (OFDM)
Key Terms (3 of 4) • PEAP • Radio Frequency Identification (RFID) • RC4 stream cipher • Remote wiping • Replay attack • Rogue access point • Rooting • Screen locking • Service set identifier (SSID) • Short Message Service (SMS) • Sideloading • Site survey • Storage segmentation
Key Terms (4 of 4) • WiMAX • Wired Equivalent Privacy (WEP) • Wireless Application Protocol (WAP) • Wireless Transport Layer Security (WTLS) • ZigBee • Temporal Key Integrity Protocol (TKIP) • USB OTG (USB On-The-Go) • WAP gap • War-chalking • War dialing • War driving • Wi-Fi Protected Access 2 (WPA2)
Introduction to Wireless Networking (1 of 3) • Wireless networking is the transmission of packetized data by means of a physical topology that does not use direct physical links. • Bluetooth is a short-range wireless protocol typically used on small devices such as mobile phones. • Wireless is problematic from a security standpoint. • Wireless does away with the physical limitations. • If attacker gets close enough to signal’s source he can listen to the access point and clients talking in order to capture all the packets for examination.
Introduction to Wireless Networking (2 of 3) • There are several different wireless bands in common use today. • Wi-Fi series refers to the 802.11 Wireless LAN standards certified by the Wi-Fi Alliance. • WiMAX refers to the set of 802.16 wireless network standards ratified by the WiMAX Forum. • ZigBee is a low-power, personal area networking technology described by the IEEE 802.15.4 series.
Introduction to Wireless Networking (3 of 3) Figure 12.1 Wireless transmission extending beyond the facility’s walls
Mobile Phones (1 of 2) • Today’s smartphones support multiple wireless data access methods. • This includes 802.11, Bluetooth, and cellular. • The Wireless Application Protocol (WAP) attempted to satisfy the needs for more data on mobile devices, but it is falling by the wayside as the mobile network capabilities increase. • The need for more and more bandwidth has pushed carriers to adopt a more IP-centric routing methodology.
Mobile Phones (2 of 2) Today’s phones allow you to carry computers in your pocket. Early cell phones just allowed you to make calls.
Wireless Application Protocol (1 of 5) • WAP was introduced to compensate for the relatively low amount of computing power on handheld devices as well as the generally poor network throughput of cellular networks. • Wireless Transport Layer Security (WTLS) encryption scheme encrypts the plaintext data and then sends it over the airwaves as ciphertext. • The originator and the recipient both have keys to decrypt the data and reproduce the plaintext.
Wireless Application Protocol (2 of 5) • WTLS uses a modified version of the Transport Layer Security (TLS) protocol. • WTLS supports several bulk encryption algorithms. • WTLS implements integrity through the use of message authentication codes (MACs). • The TLS protocol that WTLS is based on is designed around Internet-based computers. • WTLS must cope with small amounts of memory and limited processor capacity.
Wireless Application Protocol (3 of 5) • The WTLS protocol is designed around more capable servers than devices and can allow connections with little to no security. • Clients with low memory or CPU capabilities cannot support encryption which greatly reduces confidentiality. • Authentication is optional and omitting it leaves the connection vulnerable to a man-in-the-middle–type attack. • General flaws in the protocol’s implementation exist. • Known security vulnerabilities include the chosen plaintext attack, the PKCS #1 attack, and the alert message truncation attack.
Wireless Application Protocol (4 of 5) • The chosen-plaintext attack works on the principle of a predictable initialization vector (IV). • Concern over the WAP gap involves confidentiality of information where the two different networks meet the WAP gateway. • WTLS acts as the security protocol for the WAP network, and TLS is the standard for the Internet. • The WAP gateway has to perform translation from one encryption standard to the other.
Wireless Application Protocol (5 of 5) Figure 12.2 The WAP gap shows an unencrypted space between two enciphered connections.
3G Mobile Networks • Several competing data transmission standards, such as HSPA and EVDO, exist for 3G networks. • All standards include transport layer encryption protocols to secure the voice traffic traveling across the wireless signal as well as the data sent by the device. • KASUMI is the proposed 3G cryptographic standard. • This modified version of the MISTY1 algorithm uses 64-bit blocks and 128-bit keys. • Multiple attacks have been launched against this cipher.
4G Mobile Networks • 4G can support high-quality VoIP connections, video calls, and real-time video streaming. • True 4G would require a firm to meet all of the technical standards issued by the ITU, including specifications that apply to the tower side of the system. • Most 4G deployments are continuations of technologies already deployed—just newer evolutions of standards.
SATCOM • SATCOM (Satellite Communications) is the use of terrestrial transmitters and receivers and satellites in orbit to transfer the signals. • SATCOM can be one way, as in satellite radio, but for most communications two-way signals are needed. • In high-density urban areas • Cost and line-of-sight issues make SATCOM a costly option. • In rural areas or remote areas, or mobile areas such as at sea • SATCOM is one of the only options for communications.
Bluetooth (1 of 3) • Bluetooth is a short-range (approx. 32 feet), low-power wireless protocol transmitting in the 2.4 GHz band. • Bluetooth transmits data in Personal Area Networks (PANs) through mobile phones, laptops, printers, and audio devices. • Version 1.2 allows speeds up to 721 Kbps and improves resistance to interference over version 1.1. • Bluetooth 2.0 introduced enhanced data rate (EDR), which allows the transmission of up to 3.0 Mbps.
Bluetooth (2 of 3) Figure 12.3 Headsets and cell phones are two of the most popular types of Bluetooth-capable devices.
Bluetooth (3 of 3) • Bluetooth 3.0 has the capability to use an 802.11 channel to achieve speeds up to 24 Mbps. • Bluetooth 4.0 standard with support for three modes: classic, high speed, and low energy. • Bluetooth 4 introduces a new method to support collecting data from devices that generate data at a very low rate. • Bluetooth features easy configuration of devices to allow communication, with no need for network addresses or ports.
Bluetooth Attacks • Bluetooth is open to connection and attack from outside the intended sender and receiver. • Several different attack modes have been discovered that can be used against Bluetooth systems. • Software and protocol updates have helped to improve the security of the protocol. • Almost all phones now keep Bluetooth turned off by default, and they allow you to make the phone discoverable for only a limited amount of time.
Near Field Communication • Near field communication (NFC) is a set of wireless technologies. • NFC enables smartphones and other devices to establish radio communication over a short proximity, typically a distance of 10 cm (3.9 in) or less. • This technology did not see much use until recently when it started being employed to move data between cell phones and in mobile payment systems. • NFC is likely to become a high use technology in the years to come.
ANT • A multicast wireless sensor network technology that operates in the 2.4-GHz ISM band. • ANT is a proprietary method but has open access and a protocol stack to facilitate communication. • ANT is conceptually similar to Bluetooth LE • ANT is oriented toward usage with sensors, such as heart rate monitors, fitness devices, and personal devices. • ANT uses a unique isosynchronous network technology.
Infrared • A band of electromagnetic energy just beyond the red end of the visible color spectrum. • IR made its debut in computer networking as a wireless method to connect to printers. • Now that wireless keyboards, wireless mice, and mobile devices exchange data via IR, it seems to be everywhere. • IR cannot penetrate walls but bounces off them. • IR cannot penetrate other solid objects. • Items stacked in front of transceiver cause signal loss.
USB • The ubiquitous standard for connecting devices with cables. • USB ports have greatly expanded users’ ability to connect devices to their computers. • USB ports automatically recognize a device being plugged into the system and usually work without the user needing to add drivers or configure software. • Virtually anything that can consume or deliver data connects via USB. • USB drive keys: flash memory with a USB interface.
IEEE 802.11 Series • 802.11 was a new standard for sending packetized data traffic over radio waves in the unlicensed 2.4 GHz band. • This group of IEEE standards is also called Wi-Fi. • A device marked as Wi-Fi Certified adheres to the standards of the Wi-Fi alliance. • Direct-sequence spread spectrum (DSSS) • A modulation type that spreads the traffic sent over the entire bandwidth. • Orthogonal frequency division multiplexing (OFDM)
802.11: Individual Standards (1 of 4) • The 802.11b protocol provides for multiple-rate Ethernet over 2.4 GHz spread-spectrum wireless. • Most common layout is a point-to-multipoint environment. • 802.11a uses a higher band and has higher bandwidth. • It operates in the 5 GHz spectrum using OFDM and supports rates of up to 54 Mbps. • The higher frequency shortens the usable range • The 802.11g standard uses portions of both 802.11a and 802.11b.
802.11: Individual Standards (2 of 4) • All these protocols operate in bands that are “unlicensed” by the FCC. • The 802.11 standard includes attempts at rudimentary authentication and confidentiality controls. • Authentication is handled in its most basic form by the 802.11 access point (AP), forcing the clients to perform a handshake when attempting to “associate” to the AP. • Association is the process required before the AP will allow the client to talk across the AP to the network.
802.11: Individual Standards (3 of 4) • Association occurs only if the client has all the correct parameters needed in the handshake, among them the service set identifier (SSID). • The SSID is a phrase-based mechanism that helps ensure that you are connecting to the correct AP. • This SSID phrase is transmitted in all the access point’s beacon frames. • It is an 802.11 management frame for the network.
802.11: Individual Standards (4 of 4) • Typically, access to actual Ethernet segments is protected by physical security measures. • A typical wireless installation broadcasts the network right through the physical controls that are in place.
Attacking 802.11 (1 of 4) • Wireless is a popular target for several reasons: • Access gained from wireless • Lack of default security • Wide proliferation of devices • Anonymity • Low cost of the equipment needed
Attacking 802.11 (2 of 4) • Locating wireless networks was originally termed war-drivingan adaptation of the term war-dialing. • War-dialing is the process of dialing a list of phone numbers looking for modem-connected computers. • War-drivers drive around with a wireless locater program recording the number of networks found and their locations. • War-chalkingstarted with people using chalk on sidewalks to mark some of the wireless networks they found.
Attacking 802.11 (3 of 4) • The most common tools for an attacker to use are reception-based programs that listen to the beacon frames output by other wireless devices, and programs that promiscuously capture all traffic. • One of the more commonly used tools is Wireshark. • Other common tools include Aircrack-ng suite, Kismet, NetSurveyor, Vistumbler, and NetSpot.
Attacking 802.11 (4 of 4) • Once an attacker has located a network, and assuming they cannot directly connect and start active scanning and penetration of the network, the attacker will use the best attack tool there is: a network sniffer. • Popular wireless sniffers are Wireshark and Kismet. • After the limited security functions of a wireless network are broken, the network behaves exactly like a regular Ethernet network and is subject to the exact same vulnerabilities.
WEP (1 of 2) • Wired Equivalent Privacy (WEP) uses a cipher to encrypt the data as it is transmitted through the air. • WEP encrypts the data traveling across the network with an RC4 stream cipher, attempting to ensure confidentiality. • WEP supports two key lengths typically referred to as 64 and 128 bits.
WEP (2 of 2) • Manufactures use 152-bit WEP keys. • In all cases, 24 bits of the overall key length are used for the initialization vector (IV). • Biggest weakness of WEP: • IV problem exists regardless of key length • IV always remains at 24 bits, and IVs can frequently be repeated due to the limited size. • Most APs have the ability to lock in access only to known MAC addresses, providing a limited authentication capability.
Current Security Methods (1 of 7) • The Wi-Fi Alliance developed Wi-Fi Protected Access (WPA) to improve upon WEP. • The 802.11i standard is the IEEE standard for security in wireless networks. • Also known as Wi-Fi Protected Access 2 (WPA2). • Uses 802.1X to provide authentication • Can use Advanced Encryption Standard (AES) as the encryption protocol • Uses the Temporal Key Integrity Protocol (TKIP) • Uses AES with the Counter Mode with CBC-MAC Protocol
Current Security Methods (2 of 7) • TKIP works by using a shared secret combined with the card’s MAC address. • A new key is generated and mixed with the IV to make per-packet keys that encrypt a single packet using the same RC4 cipher used by traditional WEP. • CCMP is actually the mode in which the AES cipher is used to provide message integrity. • CCMP requires new hardware to perform the AES encryption. • 802.11i corrects the weaknesses of WEP.
Current Security Methods (3 of 7) • WPA uses the flawed WEP algorithm with theTemporal Key Integrity Protocol (TKIP). • TKIP employs a per-packet key, generating a new 128-bit key for each packet. • Temporal Key Integrity Protocol (TKIP) was created as a stopgap security measure to replace WEP. • Did not require the replacement of legacy hardware • Mixes a secret root key with the IV before RC4 encryption • Vulnerable to a number of similar WEP attacks • No longer considered secure
Current Security Methods (4 of 7) • IEEE 802.11i is the standard for security in wireless networks and is also known as Wi-Fi Protected Access 2 (WPA2). • Uses 802.1x to provide authentication and uses the Advanced Encryption Standard (AES) for encryption • Uses the AES block cipher • Wi-Fi Protected Setup (WPS) provides an easy method of configuring wireless networks. • WPS uses an eight-digit PIN to configure wireless devices. • It is susceptible to a brute-force attack.
Current Security Methods (5 of 7) • Steps in setting Up WPA2 are: • First choose a security framework • When configuring an adapter to connect to an existing network, you need to match the choice of the network. • For security purposes, you should choose WPA2-Personal or WPA2-Enterprise. • Choose AES encryption • Choose the network security key
Current Security Methods (6 of 7) Figure 12.5 WPA2 setup options in Windows
Current Security Methods (7 of 7) • PSK vs. Enterprise vs. Open System • When building out a wireless network, you must decide how you are going to employ security on the network. • WPA and WPA2 two methods to establish a connection: • PSK and Enterprise • WEP-based systems two options: • Open System authentication and shared key authentication
Application Protocols (1 of 10) • Wireless networks have a need for secure authentication protocols. • EAP • Extensible Authentication Protocol (EAP) is defined in RFC 2284 (obsoleted by 3748). • EAP-TLS relies on Transport Layer Security (TLS) • EAP-TTLS works with the server authenticating to the client with a certificate, but the protocol tunnels the client side of the authentication, allowing the use of legacy authentication protocols
Application Protocols (2 of 10) • LEAP • Lightweight Extensible Authentication Protocol (LEAP) is a proprietary EAP designed by Cisco • Being phased out for newer protocols: PEAP or EAP-TLS • PEAP • PEAP, or Protected EAP, is an open standard. • Developed to protect the EAP communication by encapsulating it with TLS • Designed assuming a secure communication channel • Widely supported by vendors for use over wireless networks
Application Protocols (3 of 10) • EAP-FAST • EAP–Flexible Authentication via Secure Tunneling is described in RFC-4851 and proposed by Cisco to replace LEAP. • Offers a lightweight, tunneling protocol to enable authentication. • Distinguishing characteristic is the passing of a Protected Access Credential (PAC) that’s used to establish a TLS tunnel through which client credentials are verified.
Application Protocols (4 of 10) • EAP-TLS • EAP-TLS is an IETF open standard (RFC 5216) that uses the Transport Layer Security (TLS) protocol to secure the authentication process. • One of the most secure implementations • Because common implementations employ client-side certificates. • An attacker must also possess the key for the client side certificate to break the TLS channel.
Application Protocols (5 of 10) • EAP-TTLS • Is an extension of TLS called Tunneled TLS • The authentication process is protected by the tunnel from man-in-the-middle attacks, • Client certificates can be used but not required • Makes this easier to set up than EAP-TLS for clients without certificates.