CompTIA Security+ SYO-401

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Troubleshoot security issues Tutorial

1 Given a scenario Troubleshoot Security Issues Related to Wireless Networking

We need to safeguard the wireless networks, as they are vulnerable to attacks. These attacks put our network in a compromising situation. We need to devise some troubleshooting techniques to overcome these attacks. Let’s jump to the next screen and start the lesson with its objectives. At the end of this lesson, you will be able to: • Comprehend the basics of wireless networking, • State the standards of wireless networks, • Describe channels of wireless networks, and • Troubleshoot security issues related to wireless networking.

2 Wireless Networking

In this topic, you will learn about Wireless Networking, its standards and channels. The presence of an efficient and secure wireless network is very essential. We can communicate through wireless networks due to the radio waves that transmits our messages. A perfect example of wireless network is a Wi-Fi that you use at home and office. Nowadays, it is available at restaurants, cafe shops, and malls. This triggers a question, will anybody and everybody using wireless network be able to access the information transmitted in the air? We would say, NO! It is correct only if the wireless network is secured with accurate securities and passwords. It is of utmost importance to use multiple layers of leading encryptions and authentication methods when using a wireless network. The only way to keep your wireless network secure is to turn it OFF when not in use. Though we have highly advanced securities, there are also many ways to break the wireless system technology. Throughout this lesson, we will dig deeper into methods of securing wireless networks, and identifying ways to make them immune to attacks. This would require layers of encryption and authentication, such as 802.1X wireless port security and other forms of network access control. Now that we know wireless technologies work on radio frequencies to send data through air, let’s see the types of wireless network topologies. There are two main types of topologies, Ad hoc mode and Infrastructure mode. The wireless device connecting to another device within the same network, and thereby creating a peer-to-peer network is referred to as the Ad-hoc mode. Infrastructure mode means using an infrastructure to connect to the network. The wireless devices that connect to access points and wired network, or even a Wi-Fi controller that feeds into a Wi-Fi network, are examples of the Infrastructure mode. Business environment networks contain more infrastructure mode than the ad hoc peer-to-peer mode. But the ad hoc mode has an advantage. It doesn’t need you to purchase expensive infrastructure network equipment. IEEE, the organization that develops I.T Standards, has several standards for Wi-Fi. In this lesson, we will study the following standards: 802.11a, 802.11b, 802.11n, and 802.11g. There is also an emerging 802.11ac, but now we will focus on the mentioned four standards. We know that radio has channels. Similarly, wireless networks that run on radio frequencies have channels. Each frequency range is known as a Channel. 802.11b/g/n run on the 2.4 GHz radio frequency. Each of these frequencies consist of channels. 2.4 GHz range has channels from 1 to 13, where channels 1, 6, and 11 are considered as no-bounce channels. This means, there can be multiple signals on these three channels, and they will still not conflict with one another.

3 Troubleshoot Security Issues Related to Wireless Networking

In this topic, you will learn about troubleshooting security issues related to wireless networks. The saying, "The only thing that is constant is change" is applicable in the case of technologies. Technologies are changing rapidly, yet we find wireless networks are weak, and we need to find a way to deal with constant threats. It is important to understand the wireless technology, and security practices that can be put in place to protect networks. Now, let’s see the types of security measures to troubleshoot issues related to the wireless network. We begin with Wi-Fi Encryption and Authentication. Here, we learn how users will be authenticated to the network over the wireless transmission. Moreover, it is important that authentication includes encryption, so that a malicious user is unable to steal credentials by grabbing packets transmitted in the air. The level of encryption should be such that if a data packet is grabbed, it is not easy for a hacker to crack the encryption and abuse the information. The original Wi-Fi encryption was known as WEP or Wired Equivalent Privacy, and today it is replaced by WPA and WPA 2. Wired Equivalent Privacy was an early technology that was to revolutionize Wi-Fi standard of encryption. WEP uses a pre-shared key or PSK that router knows. This meant, users trying to access the network would be authenticated only if they enter the network’s PSK. WEP aimed to make the Wi-Fi network as secure as plugged in with a wire. WEP failed to do so, because it uses an RC4 symmetric encryption algorithm. This algorithm uses 764 to 128 bits for encryption. It uses an Initialization Vector or IV {Eye We} of only 24 bits. This is a randomly generated value, and is sent in the packets header. There are limited number of possible combinations in an IV. This means, anyone who is aware of these combinations can easily crack them. Most experts say that WEP combination or security could be broken within 3 minutes. So, if you are thinking to use only WEP as your security, then it is as good as not having any security. After the failure of WEP, we needed some solution to secure wireless networks. Hence, Wi-Fi Protected Access or WPA was designed. It uses a longer key of 128 bits, and a technology that changes encryption keys for every sent packet. This is known as Temporal Key Integrity Protocol or TKIP. WEP has improved in many ways with the help of EAP or Extensible Authentication Protocol. EAP supports several methods of authentication that include Kerberos, tokens, key cards, certificates, and other measures. Moreover, it uses 802.1x packet encapsulation for transmission of data. This requires identity proof of the sender and recipient before releasing the information to the destination The two most common types of EAP are LEAP and PEAP. LEAP stands for Lightweight Extensible Authentication Protocol, while PEAP is Protected Extensible Authentication Protocol. LEAP was created and used by CISCO to work with 802.1x. PEAP uses TLS to transport the encapsulated data. There are multiple types of WPA, namely WPA Personal and WPA Enterprise.

4 WPA Personal

WPA Personal is configured at the access point or on the devices within the network. It is configured with a pre-shared key or PSK, and the password is used to encrypt and decrypt the data exchanged between the two devices. This is mostly found on home networks or small business networks. WPA Enterprise uses 802.1X standard and a central authentication server. Enterprise uses a server such as RADIUS to store credentials and authentication methods on the network. This is used by large companies, which is considered secure but complex to set up.Wi-Fi Protected Access 2 is the development over WPA. It uses a Cipher Block Chaining Message Authentication Code Protocol or CCMP. This provides data privacy integrity and authentication on wireless networks. Additionally, it uses Advanced Encryption Standard or AES, and supports 128, 192, and 256 bit encryption. Some of the key points to be remembered for WPA 2 are: • Just like WPA, WPA 2 enables you to implement concepts of Personal and Enterprise WPA 2. • WPA 2 Personal and WPA 2 Enterprise are stronger than their WPA counterparts. • WPA 2 Enterprise is stronger than WPA 2 Personal, WPA Enterprise, and WPA Personal. • The WPA and WPA 2 types are stronger than WEP and it is recommended to avoid WEP. As stated earlier, Extensible Authentication Protocol or EAP is an authentication protocol used in wireless networks. There are 5 types of EAP that act as a framework or foundation for deeper authentication security. These types include: EAP-TLS, EAP-PSK, EAP-MD5, LEAP, and PEAP. We will focus on only two types, LEAP and PEAP. Additionally, there is another type of EAP known as EAP-TTLS. This adds tunneling to the TLS channel, and is used during authentication. Many routers include WPS, which is a series of EAP messages that require a connecting user to react to the router’s signal in a certain way like entering a pin. This is not recommended as it is susceptible to brute force attacks. Lightweight EAP is an extension of EAP. It is replaced by PEAP or Protected EAP. LEAP was originally designed by Cisco as a solution to the weak WEP. LEAP requires mutual authentication, which means both senders and receivers must authenticate. But it’s susceptible to dictionary attacks. Cisco does not recommend LEAP anymore, and it does not support Windows. Protected EAP is a combination of CISCO, RSA SecurID, Software Authenticators, and Microsoft to create an authentication protocol that replaces LEAP. Windows supports it by default, and it can be used across multiple platforms and networks. Before PEAP, Windows favored EAP-TLS. Both EAP-TTLS are similar, but PEAP is considered more secure. The entire channel between clients is encrypted with a PEAP connection.MAC filtering is one of the ways to secure wireless networks. It is a part of the 802.1X standard for wireless port security. Access points and other devices offer the ability of MAC filtering. Enabling MAC filtering is also known as Network Lock. MAC filtering ensures that once a wireless device is authenticated through Wi-Fi standards such as a passphrase or RADIUS, the device is assigned a specific MAC address. It compares and gives a list of devices allowed on the Wi-Fi network. This is another level of security that should be used in conjunction with other wireless securities. Disabling SSID is another standard practice recommended with other authentications, encryptions, and security methods. SSID is a broadcast ID sent in the air by an Access Point to identify the address. The broadcasted SSIDs are the Wi-Fi networks listed on your computer. Disabling SSID broadcast requires the user to know the SSID to connect to the network. From the aspect of wireless security, this practice is weak because network packets transmitted in the air remain active, and secretly contain the SSID information. Obtaining this information is not a tough task for an experienced hacker. Disabling SSID might avoid accidental pickups of the SSID, but it is not recommended to use this as the only method of authentication.

5 Antenna Placement and Power control

We use passwords and security for our wireless devices to avoid the data from getting hacked. Applying securities passwords won’t always help. You need to place your router in the middle of the area as a precaution. This is important because if placing the router is not considered, then there are certain areas of your building without access to the network. From a security standpoint, you should try and minimize signal strength emanating outside the walls of your desired area. For example: If you have an omnidirectional antenna, and it is placed against the back wall rather than the center of your building, people outside and behind the building are able to locate and attempt to access your wireless network. Additionally, it is as important to know the antenna types you use as the placement. Another feature of antenna that helps secure your network is managing Power level controls. They can be configured to help control the area in which people connect to the wireless network. Power level controls are features on some antenna that let you determine the power of the broadcasted signal. You can lower the power level and prevent the signal from going beyond your walls. Moreover, you can strengthen the signal to ensure the entire building is covered. While setting wireless infrastructure, consider the types of antennae you prefer along with power level and placement. The most common and a well-known antenna type is Omni directional. They are present throughout the arc of 360 degree outward. These are usually placed in the center of rooms or buildings that need Wi-Fi access. If the antenna is placed incorrectly, there are chances people outside the organization area can access the network. The other type of antenna is Directional antenna. These push the signal out in a single direction. This is good for the edges of buildings or perimeters of an area so the signal goes inward, and not out of the building. Captive portal allows the public to access Wi-Fi, but this is fulfilled only when they authenticate on the webpage. This is often a disclaimer or terms of use for the guest. Before you access the network, you must either log on or accept the terms of use. Until the person visits the portal and authenticates, or performs required actions, there is no access to the Internet or network resources. This helps in separation of public and private networks, and resources, as well as limiting the liability of people using your network. Captive portals help you allow visitors to your facility and access wireless Internet. When you take the decision on how to use the antenna types, setting power levels, placing antennas, and configuring access points, you have to be really careful. A site survey is done with Wi-Fi tools to canvas your building. You check to confirm, how far your signal travels, and locate dead spots for the wireless signal. Moreover, you need to ensure only authorized users connect to your access points, and rogue or unauthorized access points are not placed within your premises. Site surveys should be done regularly to ensure you are familiar with the current wireless network map, and keep an eye on unsanctioned Wi-Fi devices, which may be malicious in nature. Many times when remote users try connecting to your network, they may be using public Wi-Fi at coffee shops or hotels. You want to make sure the information that is transmitted over these open networks is protected by an Encrypted VPN tunnel with protocols such as IPsec or SSL. Open Wireless means, you can connect anywhere in the world. But if the connection is not secured, there is high possibility of hackers meddling with your network configuration, and getting hold of private data. Using a VPN tunnel will help you prevent such intrusions. Your new company uses a SOHO router, and its wireless network can be accessed by people outside the office building. These people are not authorized, hence they shouldn’t have the credentials. After a day, you discover the security on the router is set to WEP. Being a System Administrator, it is your job to prevent such breaches. What would you do without investing in a new equipment? The Wireless Network signal is traveling outside the walls of the network. This means, the SSID is broadcasted beyond the building walls, and unauthorized people gained access by cracking the WEP. The solution to prevent these kind of security breaches is given below. Enable WPA or WPA 2 encryption for authentication. Turn on MAC filtering, and list only the devices within your company. Perform a site survey to see where the signal is traveling outside of the building, and then work on antenna placement or radio power to minimize leakage of the signal from your walls.

7 Summary

Let us summarize the topics covered in this lesson: • Wireless network is a modern technology famous for its handy use. • The Original Wi-Fi encryption was known as WEP or Wired Equivalent Privacy. • Wi-Fi Protected Access 2 is the development over WPA. It uses CCMP or Cipher Block Chaining Message Authentication Code Protocol. • MAC filtering is one of the ways to secure a wireless network. It is part of the 802.1X standard for wireless port security. • With site surveys, you can identify how far your signal travels, and locate dead spots for the wireless signal. This concludes the lesson, ‘Troubleshoot Security Issues Related to Wireless Networking.’ The next lesson is ‘Introduction to the Importance of Risk-related Concepts.’

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  • PMP, PMI, PMBOK, CAPM, PgMP, PfMP, ACP, PBA, RMP, SP, and OPM3 are registered marks of the Project Management Institute, Inc.

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