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Terms in this set (29)

Migrate the FTP server from the internal network to a screened subnet

Explanation
OBJ-4.1: A screened subnet (formerly called a demilitarized zone or DMZ) is a perimeter network that protects an organization's internal local area network (LAN) from untrusted traffic. A screened subnet is placed between the public internet and private networks. Public servers, such as the FTP server, should be installed in a screened subnet so that additional security mitigations like a web application firewall or application-aware firewall can be used to protect them. SFTP (Secure File Transfer Protocol) is a file transfer protocol that leverages a set of utilities that provide secure access to a remote computer to deliver secure communications by leveraging a secure shell (SSH) connection to encrypt the communication between the client and the server. This will prevent an attacker from eavesdropping on the communications between the SFTP server and a client, but it will not prevent an attacker from exploiting the SFTP server itself. An implicit deny is when a user or group is not granted specific permission in the security settings of an object, but they are not explicitly denied either. This is a best practice to enable, but the FTP server would still have some open ports, such as ports 20 and 21, to operate. These ports could then be used by the attacker to connect to the FTP server and exploit it. Adding a deny rule to the firewall's ACL that blocks port 21 outbound would simply prevent internal network users and servers from accessing external FTP servers. This would in no way prevent the exploitation of the company's FTP server since it has port 21 open and listening for inbound connections.
Radius

Explanation
OBJ-5.4: Captive portals usually rely on 802.1x, and 802.1x uses RADIUS for authentication. The IEEE 802.1x standard is a network authentication protocol that opens ports for network access when an organization authenticates a user's identity and authorizes them for access to the network. This defines port security. The user's identity is determined based on their credentials or certificate, which is confirmed by the RADIUS server. The Remote Authentication Dial-in User Service (RADIUS) is used to manage remote and wireless authentication infrastructure. Users supply authentication information to RADIUS client devices, such as wireless access points. The client device then passes the authentication data to an AAA (Authentication, Authorization, and Accounting) server that processes the request. Secure Sockets Layer (SSL) is a security protocol developed by Netscape to provide privacy and authentication over the Internet. SSL is application-independent that works at layer 5 [Session] and can be used with a variety of protocols, such as HTTP or FTP. Client and server set up a secure connection through PKI (X.509) certificates. Carrier-sense multiple access with collision avoidance (CSMA/CA) is a type of network multiple access method that uses carrier sensing, but nodes attempt to avoid collisions by beginning transmission only after the channel is sensed to be idle. CSMA/CA occurs in the background when communicating with a wireless access point and would not prevent the user from authenticating to the captive portal. A WPA2 security key is a preshared password used to authenticate and connect to a wireless access point. If the user connected to the SSID, then the WPA2 security key was valid.