The system administrator has been notified that many users are having difficulty connecting to the company’s wireless network. They take a new laptop and physically go to the access point and connect with no problems. Which of the following would be the MOST likely cause?
A. The certificate used to authenticate users has been compromised and revoked. B. Multiple war drivers in the parking lot have exhausted all available IPs from the pool to deny access. C. An attacker has gained access to the access point and has changed the encryption keys. D. An unauthorized access point has been configured to operate on the same channel.
Answer: D
Explanation: Wireless Access Points can be configured to use a channel. If you have multiple access points within range of each other, you should configure the access points to use different channels. Different channels use different frequencies. If you have two access points using the same channel, their Wi-Fi signals will interfere with each other. The question states that that many users are having difficulty connecting to the company’s wireless network. This is probably due to the signal being weakened by interference from another access point using the same channel. When the administrator takes a new laptop and physically goes to the access point and connects with no problems, he is able to connect because he is near the access point and therefore has a strong signal.
A user has plugged in a wireless router from home with default configurations into a network jack at the office. This is known as:
A. an evil twin. B. an IV attack. C. a rogue access point. D. an unauthorized entry point.
Answer: C
Explanation: A rogue access point is a wireless access point that should not be there. In this question, the wireless router has been connected to the corporate network without authorization. Therefore, it is a rogue access point. A rogue access point is a wireless access point that has either been installed on a secure company network without explicit authorization from a local network administrator, or has been created to allow a hacker to conduct a man-in-the-middle attack. Rogue access points of the first kind can pose a security threat to large organizations with many employees, because anyone with access to the premises can install (maliciously or non-maliciously) an inexpensive wireless router that can potentially allow access to a secure network to unauthorized parties. Rogue access points of the second kind target networks that do not employ mutual authentication (client-server server-client) and may be used in conjunction with a rogue RADIUS server, depending on security configuration of the target network. To prevent the installation of rogue access points, organizations can install wireless intrusion prevention systems to monitor the radio spectrum for unauthorized access points.
The practice of marking open wireless access points is called which of the following?
A. War dialing B. War chalking C. War driving D. Evil twin
Answer: B
Explanation: War chalking is the act of making chalk marks on outdoor surfaces (walls, sidewalks, buildings, sign posts, trees) to indicate the existence of an open wireless network connection, usually offering an Internet connection so that others can benefit from the free wireless access. The open connections typically come from the access points of wireless networks located within buildings to serve enterprises. The chalk symbols indicate the type of access point that is available at that specific spot.
Ann, the network administrator, has learned from the helpdesk that employees are accessing the wireless network without entering their domain credentials upon connection. Once the connection is made, they cannot reach any internal resources, while wired network connections operate smoothly. Which of the following is MOST likely occurring?
A. A user has plugged in a personal access point at their desk to connect to the network wirelessly. B. The company is currently experiencing an attack on their internal DNS servers. C. The company’s WEP encryption has been compromised and WPA2 needs to be implemented instead. D. An attacker has installed an access point nearby in an attempt to capture company information.
Answer: D
Explanation: The question implies that users should be required to enter their domain credentials upon connection to the wireless network. The fact that they are connecting to a wireless network without being prompted for their domain credentials and they are unable to access network resources suggests they are connecting to a rogue wireless network. A rogue access point is a wireless access point that has either been installed on a secure company network without explicit authorization from a local network administrator, or has been created to allow a hacker to conduct a man-in-the-middle attack. Rogue access points of the first kind can pose a security threat to large organizations with many employees, because anyone with access to the premises can install (maliciously or non-maliciously) an inexpensive wireless router that can potentially allow access to a secure network to unauthorized parties. Rogue access points of the second kind target networks that do not employ mutual authentication (client-server server-client) and may be used in conjunction with a rogue RADIUS server, depending on security configuration of the target network. To prevent the installation of rogue access points, organizations can install wireless intrusion prevention systems to monitor the radio spectrum for unauthorized access points.
Which of the following implementation steps would be appropriate for a public wireless hot-spot?
A. Reduce power level B. Disable SSID broadcast C. Open system authentication D. MAC filter
Answer: C
Explanation: For a public wireless hot-spot, you want members of the public to be able to access the wireless network without having to provide them with a password. Therefore, Open System Authentication is the best solution.
Open System Authentication (OSA) is a process by which a computer can gain access to a wireless network that uses the Wired Equivalent Privacy (WEP) protocol. With OSA, a computer equipped with a wireless modem can access any WEP network and receive files that are not encrypted. For OSA to work, the service set identifier (SSID) of the computer should match the SSID of the wireless access point. The SSID is a sequence of characters that uniquely names a wireless local area network (WLAN). The process occurs in three steps. First, the computer sends a request for authentication to the access point. Then the access point generates an authentication code, usually at random, intended for use only during that session. Finally, the computer accepts the authentication code and becomes part of the network as long as the session continues and the computer remains within range of the original access point. If it is necessary to exchange encrypted data between a WEP network access point and a wireless-equipped computer, a stronger authentication process called Shared Key Authentication (SKA) is required.
Ann, a security administrator, has concerns regarding her company’s wireless network. The network is open and available for visiting prospective clients in the conference room, but she notices that many more devices are connecting to the network than should be. Which of the following would BEST alleviate Ann’s concerns with minimum disturbance of current functionality for clients?
A. Enable MAC filtering on the wireless access point. B. Configure WPA2 encryption on the wireless access point. C. Lower the antenna’s broadcasting power. D. Disable SSID broadcasting.
Answer: C
Explanation: Some access points include power level controls that allow you to reduce the amount of output provided if the signal is traveling too far.
Users have been reporting that their wireless access point is not functioning. They state that it allows slow connections to the internet, but does not provide access to the internal network. The user provides the SSID and the technician logs into the company’s access point and finds no issues. Which of the following should the technician do?
A. Change the access point from WPA2 to WEP to determine if the encryption is too strong B. Clear all access logs from the AP to provide an up-to-date access list of connected users C. Check the MAC address of the AP to which the users are connecting to determine if it is an imposter D. Reconfigure the access point so that it is blocking all inbound and outbound traffic as a troubleshooting gap
Answer: C
Explanation: The users may be connecting to a rogue access point. The rogue access point could be hosting a wireless network that has the same SSID as the corporate wireless network. The only way to tell for sure if the access point the users are connecting to is the correct one is to check the MAC address. Every network card has a unique 48-bit address assigned. A media access control address (MAC address) is a unique identifier assigned to network interfaces for communications on the physical network segment. MAC addresses are used as a network address for most IEEE 802 network technologies, including Ethernet and WiFi. Logically, MAC addresses are used in the media access control protocol sublayer of the OSI reference model. MAC addresses are most often assigned by the manufacturer of a network interface controller (NIC) and are stored in its hardware, such as the card’s read-only memory or some other firmware mechanism. If assigned by the manufacturer, a MAC address usually encodes the manufacturer’s registered identification number and may be referred to as the burned-in address (BIA). It may also be known as an Ethernet hardware address (EHA), hardware address or physical address. This can be contrasted to a programmed address, where the host device issues commands to the NIC to use an arbitrary address. A network node may have multiple NICs and each NIC must have a unique MAC address. MAC addresses are formed according to the rules of one of three numbering name spaces managed by the Institute of Electrical and Electronics Engineers (IEEE): MAC-48, EUI-48, and EUI-64.
An employee connects a wireless access point to the only jack in the conference room to provide Internet access during a meeting. The access point is configured to use WPA2-TKIP. A malicious user is able to intercept clear text HTTP communication between the meeting attendees and the Internet. Which of the following is the reason the malicious user is able to intercept and see the clear text communication?
A. The malicious user has access to the WPA2-TKIP key. B. The wireless access point is broadcasting the SSID. C. The malicious user is able to capture the wired communication. D. The meeting attendees are using unencrypted hard drives.
Answer: C
Explanation: In this question, the wireless users are using WPA2-TKIP. While TKIP is a weak encryption protocol, it is still an encryption protocol. Therefore, the wireless communications between the laptops and the wireless access point are encrypted. The question states that user was able to intercept ‘clear text’ HTTP communication between the meeting attendees and the Internet. The HTTP communications are unencrypted as they travel over the wired network. Therefore, the malicious user must have been able to capture the wired communication.
TKIP and AES are two different types of encryption that can be used by a Wi-Fi network. TKIP stands for “Temporal Key Integrity Protocol.” It was a stopgap encryption protocol introduced with WPA to replace the very-insecure WEP encryption at the time. TKIP is actually quite similar to WEP encryption. TKIP is no longer considered secure, and is now deprecated.
Which of the following types of wireless attacks would be used specifically to impersonate another WAP in order to gain unauthorized information from mobile users?
A. IV attack B. Evil twin C. War driving D. Rogue access point
Answer: B
Explanation: An evil twin, in the context of network security, is a rogue or fake wireless access point (WAP) that appears as a genuine hotspot offered by a legitimate provider. In an evil twin attack, an eavesdropper or hacker fraudulently creates this rogue hotspot to collect the personal data of unsuspecting users. Sensitive data can be stolen by spying on a connection or using a phishing technique. For example, a hacker using an evil twin exploit may be positioned near an authentic Wi-Fi access point and discover the service set identifier (SSID) and frequency. The hacker may then send a radio signal using the exact same frequency and SSID. To end users, the rogue evil twin appears
as their legitimate hotspot with the same name. In wireless transmissions, evil twins are not a new phenomenon. Historically, they were known as honeypots or base station clones. With the advancement of wireless technology and the use of wireless devices in public areas, it is very easy for novice users to set up evil twin exploits.
After a recent breach, the security administrator performs a wireless survey of the corporate network. The security administrator notices a problem with the following output: MACSSIDENCRYPTIONPOWERBEACONS 00:10:A1:36:12:CCMYCORPWPA2 CCMP601202 00:10:A1:49:FC:37MYCORPWPA2 CCMP709102 FB:90:11:42:FA:99MYCORPWPA2 CCMP403031 00:10:A1:AA:BB:CCMYCORPWPA2 CCMP552021 00:10:A1:FA:B1:07MYCORPWPA2 CCMP306044 Given that the corporate wireless network has been standardized, which of the following attacks is underway?
A. Evil twin B. IV attack C. Rogue AP D. DDoS
Answer: A
Explanation: The question states that the corporate wireless network has been standardized. By ‘standardized’ it means the wireless network access points are running on hardware from the same vendor. We can see this from the MAC addresses used. The first half of a MAC address is vendor specific.
The second half is network adapter specific. We have four devices with MAC addresses that start with 00:10:A1. The “odd one out” is the device with a MAC address starting FB:90:11. This device is from a different vendor. The SSID of the wireless network on this access point is the same as the other legitimate access points. Therefore, the access point with a MAC address starting FB:90:11 is impersonating the corporate access points. This is known as an Evil Twin.
An evil twin, in the context of network security, is a rogue or fake wireless access point (WAP) that appears as a genuine hotspot offered by a legitimate provider. In an evil twin attack, an eavesdropper or hacker fraudulently creates this rogue hotspot to collect the personal data of unsuspecting users. Sensitive data can be stolen by spying on a connection or using a phishing technique. For example, a hacker using an evil twin exploit may be positioned near an authentic Wi-Fi access point and discover the service set identifier (SSID) and frequency. The hacker may then send a radio signal using the exact same frequency and SSID. To end users, the rogue evil twin appears as their legitimate hotspot with the same name. In wireless transmissions, evil twins are not a new phenomenon. Historically, they were known as honeypots or base station clones. With the advancement of wireless technology and the use of wireless devices in public areas, it is very easy for novice users to set up evil twin exploits.