Network Security Flashcards

1
Q

CIA Triad

A

Confidentiality
Integrity
Availability

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2
Q

Confidentiality

A

Keeping the data private & safe
(Encryption, Authentication to access resources)

Encryption ensures data can only be read (decoded) by intended recipient (Asymmetric/Symmetric)

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3
Q

Symmetric Encryption

A

Both sender & receiver use the same key

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4
Q

DES

A
Data Encryption Standard
Developed mid-1970s
56-bit key
Used by SNMPv3
Considered weak today
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5
Q

3DES

A

Triple DES
Uses three 56-bit keys (168-bit total)
Encrypt, decrypt, encrypt

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6
Q

AES

A

Advanced Encryption Standard
Preferred symmetric encryption standard
Used by WPA2
Available in: 128-bit, 192-bit, 256-bit

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7
Q

Asymmetric Encryption

A

Uses different keys for sender/receiver
RSA is most popular implementation
RSA commonly used with PKI (public key infrastructure)
PKI is used to encrypt data between web browser & shopping site
Can be used for secure emails
Sender/receiver use different keys to encrypt/decrypt

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8
Q

Integrity

A

Ensures data has not been modified in transit
Verifies the source the traffic originates from

Integrity violations:
Defacing a corporate web page
Altering an e-commerce transaction
Modifying electronically stored financial records

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9
Q

Hashing (Integrity)

A

Sender runs string of data through algorithm
Result is a hash or hash digest

Data & hash are sent to receiver
Receiver runs data received via same algorithm & obtains a hash
Two hashes are compared (if same, data not modified)

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10
Q

Hashing Algorithms

A

MD5 (Message Digest 5)
128-bit hash digest

SHA-1 (Secure Hash Algorithm 1)
160-bit hash digest

SHA-256 (Secure Hash Algorithm 256)
256-bit hash digest

CRAMMD5 (Challenge-response Authentication Mechanism MD5)
Common variant often used in email systems

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11
Q

Network Security Attack Types

A

Confidentiality:
Attempts to make data viewable by attacker

Integrity:
Attempts to alter data

Availability:
Attempts to limit network accessibility & usability

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12
Q

Confidentiality Attacks

A
Packet capture
Wire tapping
Dumpster diving
Ping sweep
Port scan
Wireless interception
EMI
MITM
Social Engineering
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13
Q

Integrity Attacks

A

MITM
Data diddling (changes data before storage)
Trust relationship exploitation
Salami attack (many small attacks = one big attack)
Password attack
Session Hijacking
Botnets

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14
Q

Availability Attacks

A
DoS/DDoS
TCP SYN Flood
Buffer overflow
ICMP attacks (Smurf)
UDP attacks (Fraggle)
Ping of Death
Electrical disturbances
Physical environment attacks (Temperature, Humidity, Gas)
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15
Q

Protecting a Network

A
Physical controls
User training
Patching
Vulnerability Scanners
Honey pots & honey nets
Remote-access security
Security policies
Incident response
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16
Q

Vulnerability Scanners

A

Ex: Nessus, Zenmap, Nmap

Periodically test network to verify that security components are behaving as expected & detect known vulnerabilities

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17
Q

Honey Pots/Nets

A

Systems designed as an attractive target
(Trap/Distraction)

Attackers waste resources

Honey pot = single machine
Honey net = network of multiple honey pots

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18
Q

Remote Access Security

A
SSH
RADIUS (Open UDP-based auth protocol)
TACACS+ (Cisco, TCP-based auth protocol)
Kerberos (Windows domain auth protocol)
802.1X (Permits/dennies wired/wireless client access to LAN)
2FA
SSO
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19
Q

BYOD Vulnerabilities

A

Bluejacking
Unauthorized messages over bluetooth

Bluesnarfing
Unauthorized access to wireless via bluetooth

Bluebugging
Unauthorized backdoor to connect bluetooth back to attacker

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20
Q

System Lifecycle

A
Conceptual Design
Preliminary Design
Detailed Design
Production/Installation
Operations/Support
Phase Out
Disposal
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21
Q

MFA

A

Multifactor Authentication
Something you know (user/pass)
Something you have (key fobs/smart cards)
Something you are (fingerprints/retina)
Something you do (signature, pattern, passphrase)
Somewhere you are (geotagging/geofencing)

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22
Q

Packet-Filtering Firewalls

A

Permits/denies traffic based on packet header
(Source/Destination IP)
(Source/Destination Port)

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23
Q

Firewall Zones

A
Inside = Connects to corporate LAN
Outside = Connects to Internet (typically)
DMZ = Connects to devices that should have restricted access from outside zone (like web/email servers)
24
Q

UTM Devices

A

Unified Threat Management Devices
Combines firewall, router, IDS/IPS, antimalware, & more

UTM can be queried before allowing connection to network

UTM can be a physical device or cloud solution

25
Q

IDS

A

Intrusion Detection System
Passive device
Operates parallel to network
Monitors all traffic & sends alerts

26
Q

IPS

A
Intrusion Protection System
Active device
Operates in-line to the network
Monitors all traffic, sends alerts
Drops/blocks offending traffic
27
Q

Detection Methods

A

Signature-Based:
Signature contains strings of bytes (pattern) that triggers detection

Policy-Based:
Relies on specific declaration of security policy

Anomaly-Based:
Statistical anomaly - watches traffic patterns to build a baseline

Non-statistical anomaly - Admin defines patterns/baseline

28
Q

CVE

A

Common Vulnerabilities & Exposures:

A list of publicly disclosed computer security weaknesses

29
Q

Penetration Test

A

Evaluates the security of an IT infrastructure by safely trying to exploit vulnerabilities within the systems/network

30
Q

Posture Assessment

A

Assesses cyber risk posture & exposure to threats caused by misconfigurations & patching delays.

(Stay in control, strengthen position, define mission-critical components, identify strengths/weaknesses)

31
Q

Business Risk Assessment

A

Identify, understand, & evaluate potential hazards in the workplace

32
Q

Process Assessment

A

The disciplined examination of the processes used by the organization against a set of criteria

(Vendor assessment: make sure they can fit needs of the business)

33
Q

DAC (Access Control)

A

Discretionary Access Control:

An access control method where access is determined by the owner of the resource

34
Q

MAC (Access Control)

A

Mandatory Access Control:
An access control policy where the computer system gets to decide who gets access to what objects

(Unclassified, confidential, secret, top secret)

35
Q

RBAC (Access Control)

A

Role-Based Access Control:
An access model that is controlled by the system but focuses on a set of permissions versus an individual’s permissions

(Creating groups makes it easy to control permissions based around job functions)

36
Q

Zero-Trust

A

A security framework that requires users to be authenticated & authorized before being granted access to apps/data

1) Reexamine all default access controls
2) Employ prevention/defense techniques
3) Enable real-time monitoring & controls to stop malicious activity quickly
4) Ensure network’s zero-trust architecture aligns to a broader security strategy

37
Q

DMZ

A

Demilitarized Zone:

A perimeter network that protects an organization’s internal LAN from untrusted traffic

38
Q

Screen Subnet

A

Subnet in the network architecture that uses a single firewall with 3 interfaces to connect 3 dissimilar networks

(Triple-homed firewall)

39
Q

Separation of Duties

A

Prevents frauds & abuse by distributing various tasks & approval authorities across a number of different users

40
Q

Dual Control

A

Two people have to be present at the same time to do something

41
Q

Split Knowledge

A

Two people have half of the knowledge on how to do something

42
Q

Kerberos

A

Focused on authentication & authorization within a Windows domain

Provides secure authentication over an insecure network

43
Q

RADIUS

A

Provides centralized administration of dial-up, VPN, & wireless network authentication

(Authentication, Authorization, Accounting)

Accounting (Common Uses):
Port 1812 Authentication Messages
Port 1813 Accounting Messages

Proprietary RADIUS versions may use:
Port 1645 Authentication messages
Port 1646 Accounting messages

44
Q

TACACS+

A
Used to perform the role of an authenticator in an 802.1x network
RADIUS: UDP
TACACS+: TCP
Ensure port 49 is open
Excellent for Cisco devices
45
Q

802.1X

A

A standardized framework that’s used for port-based authentication on both wired/wireless networks

(Supplicant, authenticator, authentication server)

46
Q

EAP

A

Extensible Authentication Protocol:
Authentication performed using 802.1x

EAP-MD5: Simple passwords & challenge handshake auth process for remote access

EAP-TLS: Uses public key infrastructure with digital certificate on both client/server

EAP-TTLS: Digital certificate on server & password on the client for auth

EAP-FAST: Uses a protected access credential to establish mutual auth between devices (also uses TLS; Cisco upgrade from LEAP)

PEAP: Uses server certifications & AD databases to auth a password
(Protected EAP)
LEAP: Proprietary Cisco protocol
(Lightweight EAP)

47
Q

NAC

A

Network Access Control:

Ensures a device is scanned to determine its current state of security prior to being allowed network access

48
Q

NAC: Persistent Agent

A

A piece of software installed on a device requesting access to the network

49
Q

NAC: Non-Persistent Agent

A

Requires the users to connect to the network & go to a web-based captive portal to download the agent onto their device

50
Q

Infrared System

A

Displays images based on the amount of heat in a room

Identify hot spots in the room (potential gear overheating)
Easily identify where a person is in a room

51
Q

Ultrasonic Camera

A

A type of surveillance camera that uses sound-based detection

52
Q

eFuse

A

An electronic detection mechanism that can record the version of the IOS used by a switch

53
Q

Access Control Vestibule

A

AKA: Mantrap

54
Q

Smart Locker

A

A fully integrated system that allows you to keep your valuables inside

Small businesses: 69% ROI
Large enterprises: 248% ROI

55
Q

Purging/Sanitizing

A

Removes data through a means of which it cannot be reconstructed (guaranteed)

56
Q

Clearing Technique

A

Removes data with a certain amount of assurance it can’t be reconstructed