SY0-501 Chapter 4: Securing Your Network

IDSs and IPSs

inspect traffic using the same functionality as a protocol analyzer

HIDS

detect attacks on local systems such as workstations and servers; protect local resources on the host and can detect some malware that isn't detected by traditional antivirus software

NIDS

detects attacks on networks

Signature-based IDS/IPS

uses signatures to detect known attacks or vulnerabilities

Heuristic-based or Behavioral-based IDSs (Anomaly-based IDSs)

require a baseline and detect attacks based on anomalies or when traffic is outside expected boundaries

False Positive

incorrectly raises an alert indicating an attack when an attack is not active; increase workload of admin

False Negative

attack is active, but not reported

IPS

placed inline w/ traffic (in-band) and can stop attacks before they reach the internal network; actively monitor data streams, detect malicious content, prevent it from reaching a network

IDS/IPS

protect internal private networks, such as private supervisory control and data acquisition (SCADA) networks

SSL/TLS Accelerators

dedicated hardware devices that handle TLS traffic; other devices, such as a web server, can off-load TLS traffic handling to the accelerator

SSL Decryptors

allow an organization to inspect traffic, even when traffic is using SSL/TLS

Software Defined Network (SDN)

uses virtualization technologies to route traffic instead of using hardware routers and switches; separates data and control planes

Honeypots and Honeynets

appear to have valuable data and attempt to divert attackers away from live networks; security personnel use them to observe current attack methodologies and gather intel on attacks

802.1x Server

provides strong port security using port-based authentication; prevents rogue devices from connecting to a network by ensuring that only authorized clients can connect; EAP, PEAP, EAP-TTLS, EAP-FAST. Most Secure EAP Method is EAP-TLS.

Wireless Access Points (WAP)

connect wireless clients to a wired network; omnidirectional antennas

Fat AP (stand-alone AP)

everything needed to connect wireless clients to a wireless network

Thin APs

controller-based; controller configures and manages thin AP

SSID

name of wireless network; disabling SSID broadcast hides a wireless network form casual users

MAC Filtering

restrict access to wireless networks; attackers can discover authorized MACs and spoof an authorized MAC address

Directional Antennas

narrower beams and longer ranges

Ad hoc Wireless Network

2+ devices connected together w/out an AP

Wi-Fi Protected Access (WPA)

TKIP/CCMP, WPA and TKIP have been depreciated

Pre-Shared Key (PSK)

used by personal mode; easy to implement and used in many smaller wireless networks

Enterprise Mode

more secure than personal mode; adds authentication; uses 1x authentication server implemented as a RADIUS server

Open Mode

doesn't use PSK or 1x server; many hot spots use open mode when providing free wireless access to customers

EAP-TLS

most secure, requires certificate on the server and on each wireless client

EAP-TTLS and PEAP

require certificate on the server, but not the client

PEAP

often implemented w/ MS-CHAPv2.

LEAP

proprietary to Cisco and does not require certificate, replaced by EAP-FAST

Captive Portal

forces wireless clients to complete a process, such as acknowledging a policy or paying for access, before it grants them access to network

Disassociation Attack

effectively removes a wireless client form a network, forcing it to reauthenticate

WPS

allows users to easily configure a wireless device by pressing a button or entering a short PIN; NOT secure; attack can discover PIN within hours, PIN used to discover passphrase

Rogue Access Point (rogue AP)

AP placed in network w/out official authorization

Evil Twin

rogue AP with same SSID as a legitimate AP

Jamming Attack

floods a wireless frequency w/ noise, blocking wireless traffic

Initialization Vector (IV)

attack attempts to discover IV and uses it to discover passphrase

Near Field Communication (NFC)

attack uses an NFC reader to read data from mobile devices

Bluejacking

practice of sending unsolicited messages to a phone

Bluesnarfing

unauthorized access to, or theft of info from, a Bluetooth device

Wireless Replay Attack

attacker captures data sent b/w two entities, modifies it, then impersonates one of the parties by replaying the data (WPA2 using CCMP and AES prevents attacks)

Radio-Frequency ID (RFID)

attacks include eavesdropping, replay, and DoS

VPN

provides access to private networks via a public network, such as the Internet

VPN Concentrators

dedicated devices that provide secure remote access to remote users

IPsec

common tunneling protocol used w/ VPNs; secures traffic within tunnel; provides authentication w/ AH & ESP

Encapsulating Security Payload (ESP)

encrypts VPN traffic and provides confidentiality, integrity, and authentication

IPsec Tunnel Mode

encrypts entire IP packets used in the internal network; some VPNs use TLS to encrypt traffic

IPsec Transport Mode

only encrypts payload and is commonly used in private networks, but not with VPNs

Full Tunnel

encrypts all traffic after user has connected to a VPN

Split Tunnel

only encrypts traffic destined for the VPNs private network

Site-to-Site VPNs

provide secure access b/w two networks; can be on-demand or always-on VPNs

Network Access Control (NAC)

inspects clients for specific health conditions such as up-to-date antivirus software; can redirect unhealthy clients to a remediation network

Permanent/persistent NAC Agent

installed on client and stays on client

Dissolvable NAC Agent (Agentless)

downloaded and run on client when client logs on, and deleted after session ends; commonly used for employee-owned mobile devices

Remote Access Authentication

user accesses a private network from a remote location, such as w/ VPN connection

PAP

uses password or PIN for authentication; sends passwords in cleartext

CHAP

more secure than PAP and uses a handshake process when authenticating clients

MS-CHAPv2

provides mutual authentication

RADIUS

provides central authentication for multiple remote access services; relies on use of shared secrets and only encrypts password during authentication process; uses UDP

TACACS+

used by some Cisco systems as an alternative to RADIUS, uses TCP, encrypts entire authentication process and supports multiple challenges and responses

Diameter

improvement over RADIUS; uses TCP; encrypts entire authentication process, and supports many additional capabilities

Authentication, Authorization, Accounting (AAA) Protocols

RADIUS, TACACS+, and Diameter