Wireless LAN Security

Kasturi Chakraborty

Shreosi Maitra

Suvadip Banerjee

Upasona Roy

Presented by

CONTENTS

Introduction

Wireless LAN Technology Options

Types of Wireless LANs

Basic Configuration

Standards

Advantages and Disadvantages

Security issues and Solutions

Introduction

Wireless LAN is a flexible communication system

implemented as an extension to a wired LAN, using

electromagnetic waves to transmit and receive data over

air, minimizing the need for wired connections.

It is a communication network that provides connectivity to

wireless devices within a limited geographic area such as

home, school, single office, building or campus.

"Wi-Fi" is the universal standard for wireless networks and is the

wireless equivalent of wired Ethernet networks.

Wireless LAN Technology Options

o Narrowband Technology

o Spread Spectrum Technology

o Frequency-Hopping Spread Spectrum Technology

o Direct Sequence Spread Spectrum Technology

o Infrared Technology

Basic Configuration

Types of Wireless LANs

Standards

1) IEEE 802.11

2) IEEE 802.11b

3) IEEE 802.11a

4) IEEE 802.11g

5) IEEE 802.11n

6) IEEE 802.11ac

Advantages

Key drivers are mobility and

accessibility.

Increased Productivity.

Improved collaboration.

No need to reconnect to the network.

Flexible installation and scalability.

Disadvantages

Very expensive.

Signal bleed over.

Environmental conditions.

Less capacity.

Is it Secure?

Someone can block the entire radio communication

channel by transmitting junk on certain frequencies and

anonymously stage a denial of service attack from your

network.

Anybody can plant viruses on our system.

The webpages can be changed.

As the number of WLAN cards grows so will the

opportunities for hackers to break into the wireless

networks.

Regardless of the technology used , WLAN security will

always be limited because users will sidestep security

features.

Security Issues & Solutions

War Driving

Eavesdropping

Denial of Service Attack

Rogue Access Points

War Driving(Access Point

Mapping) It is the act of locating and possibly exploiting connections to

wireless local area networks while driving around a city or

elsewhere using a portable computer, smartphone or personal

digital assistant (PDA).

Wireless NIC scans for wireless access points . The computer looks

for SSID (wireless network name) which is being constantly

transmitted by the access point , letting the computers know of its

presence.

The wiredriver uses software like NetStumbler (Windows) or

Kismet (Linux) to scan the airwaves for SSIDS.

The wiredriver generally configures his/her software to log any

strong unencrypted signal using GPS receiver and connect to the

access point.

Basic Configuration of War Driving

Solution for War Driving

o Do not broadcast your SSID.

o Change the default password.

o Encrypt your wireless connection using the encryption schemes.

o Filter the MAC addresses that are allowed to connect to your router.

o If you configure file sharing on your computer, make sure it is password protected.

o Use personal firewall software.

Eavesdropping

In wireless sensor networks ,any wireless network residing in the transmission

range of the transmitter can potentially decode the signal when both the

transmitter and receiver are unaware of the reconnaissance.

This involves attacks against the confidentiality of the data that is being

transmitted across the network.

There are two types of eavesdropping:

I. Passive Eavesdropping: The malicious nodes detect the information by

listening to the message transmission in the wireless broadcasting medium.

II. Active Eavesdropping: The malicious nodes actively grab the information via

sending queries to transmitters by disguising themselves as friendly nodes.

Solution for Eavesdropping

o The best way to keep your traffic secure while on Wi-Fi

hotspots is to connect to a Virtual Private Network (VPN),

maybe to your work’s network, a server you set up at your

home, or a hosted service designed specifically for

hotspot security, such as Private Wifi or Hotspot Shield.

o We must make sure any services or sites you use while on

the hotspot are secured with SSL encryption.

o The Enterprise mode of WPA2 security (also called the

802.1X or EAP mode) requires an authentication server,

commonly called a Remote Authentication Dial In User

Service (RADIUS) which prevents users from reading each

other’s traffic.

Denial of Service Attack

A denial of service (DoS) attack is an assault that can

cripple or disable a WLAN. It can slow the network to

crawling speeds or actually force it to quit working.

One form of DoS attack is the "brute force" method. This

can come in one of two forms:

I. A huge flood of packets that uses up all of the network's

resources and forces it to shut down.

II. A very strong radio signal that totally dominates the

airwaves and renders access points and radio cards

useless.

Solution for Denial of Service

AttackThis type of attack can be prevented by:

o implementing and updating firewalls.

o maintaining updated virus protection.

o ensuring strong passwords and deploy DoS detection tools,

such as AirDefense and AirMagnet in addition.

o You can protect a WLAN against DoS attacks by making the

building as resistive as possible to incoming radio signals.

Rogue Access Points

Rogue APs can be APs that are connected to the enterprise wired LAN

without authorization or APs that are not connected to the wired LAN

but that accept associations from clients.

Rogue APs can even be APs with a wireless card and a special

software package that makes them act as an AP.

Types of Rogue Aps based on security categories:

I. Non-malicious APs: The majority of the cases consist of someone

installing a rogue AP with the intent being not to bypass the

corporation's security policy but to deploy wireless as a convenience

or productivity enhancer.

II. Malicious Aps: the attacker sets up the AP to gain access to the wired

network or to disrupt the performance of the WLAN.

Rogue AP Detection

Prevention of Rogue APs

o Use of commercial tools like AirMagnet and AirDefence to

scan for rogue Aps periodically and verify their legitimacy.

o Using network Wireless Intrusion Prevention System (WIPS)

to watch the air or by using a host-resident Wireless IPS to

monitor client activity.

o Use of WLAN analyzer for Rogue AP detection.

o Smaller businesses on more limited budgets may prefer to

install stand-alone host WIPS programs like Sana Security

Primary Response Air Cover.