CompTIA Security+ Exam Prep

Cards · 214

CIA Triad

Core model guiding info security policies: Confidentiality, Integrity, and Availability.

Confidentiality

Ensures sensitive data is shielded from unauthorized reading and disclosure.

Integrity

Ensures data remains authentic, accurate, and unaltered by unauthorized parties.

Availability

Ensures services, networks, and data remain accessible to authorized users when needed.

Non-Repudiation

Assurance that an individual cannot deny the authenticity of their signature or message.

Authentication

The process of verifying the identity of a user, device, or system entity.

Authorization

The process of determining and enforcing user rights and access permissions.

Accounting

Tracking user activity and resource consumption to ensure individual accountability.

Identification

The initial claim of an identity, such as providing a username or account number.

Threat

Any circumstance or event with the potential to adversely impact assets or operations.

Vulnerability

A flaw or weakness in system design, implementation, or operations that can be exploited.

Risk

The likelihood of a threat actor exploiting a vulnerability multiplied by its impact.

Exploit

Software, command sequences, or techniques that take advantage of a vulnerability.

Risk Avoidance

Eliminating exposure to risk by halting an activity or discarding a technology.

Risk Transference

Shifting the financial or operational burden of a risk, commonly via insurance.

Risk Mitigation

Deploying security controls and countermeasures to reduce the severity or likelihood of risk.

Risk Acceptance

Acknowledging and choosing to live with a risk because mitigation costs exceed the impact.

Inherent Risk

The raw level of risk present before applying any safeguards or controls.

Residual Risk

The remaining level of risk after all existing controls and mitigations are in place.

Control Types: Technical

Security controls implemented via hardware, software, firmware, or firewalls.

Control Types: Administrative

Managerial security controls consisting of policies, training, standards, and guidelines.

Control Types: Physical

Tangible security controls like fences, locks, badges, guards, and biometric doors.

Control Functions: Preventative

Controls designed to proactively block security incidents from occurring.

Control Functions: Detective

Controls that identify, trace, and record security events while or after they happen.

Control Functions: Corrective

Controls that restore systems and mitigate damage following an incident.

Phishing

Fraudulent communication disguised as reputable to deceive targets into revealing data.

Spear Phishing

Highly targeted email attack customized to a specific individual or organization.

Whaling

Targeted phishing attack directed specifically at high-profile executives or officials.

Vishing

Social engineering scam carried out over telephone calls or voice communications.

Smishing

Phishing attacks conducted via Short Message Service (SMS) text messaging.

Social Engineering

Psychological manipulation of individuals into divulging confidential information.

Shoulder Surfing

Directly observing personal data or credentials over someone's shoulder.

Dumpster Diving

Searching through trash bins to locate passwords, notes, or sensitive documents.

Tailgating

Following an authorized individual through a secure physical door without badging in.

Piggybacking

Entering a secure area with consent from an authorized user without valid credentials.

Watering Hole Attack

Compromising a niche website frequently visited by targets to infect their systems.

Typosquatting

Registering misspelled domain names of popular sites to trick errant typists.

Pretexting

Creating an invented scenario to persuade a victim to release information.

Malware

Broad term for software created specifically to damage, disrupt, or gain illicit access.

Virus

Malicious code that replicates by inserting copies into host programs or files.

Worm

Self-replicating standalone malware that spreads across networks without human intervention.

Trojan Horse

Malware disguised as useful software that performs covert malicious operations.

Ransomware

Malware that encrypts user data and demands payment for the decryption key.

Spyware

Software that covertly monitors user behavior, keystrokes, and system activity.

Keylogger

Hardware device or program that records every stroke on a keyboard to capture secrets.

Rootkit

Malware designed to maintain privileged administrator-level access while hiding its presence.

Botnet

A network of infected computers remotely controlled by an attacker to launch attacks.

Logic Bomb

Malicious code set to execute only when specific criteria or deadlines are met.

Backdoor

An undocumented method of bypassing normal authentication to access a system.

Zero-Day Exploit

An attack targeting a newly discovered vulnerability before a vendor patch exists.

Denial of Service (DoS)

An attack that overwhelms a target system to render it inaccessible to legitimate users.

Distributed DoS (DDoS)

A DoS attack launched from multiple distributed machines or botnets simultaneously.

Man-in-the-Middle (MitM)

An attacker intercepts and potentially alters communication between two trusting parties.

ARP Poisoning

Falsifying ARP messages on a LAN to link an attacker's MAC address with a valid IP.

DNS Spoofing

Corrupting DNS cache records to redirect users to malicious duplicate websites.

Replay Attack

Valid data transmission is maliciously repeated or delayed to impersonate a session.

Pass the Hash

Using stolen password hashes rather than plain text to authenticate to remote servers.

Brute Force Attack

Attempting every possible combination of characters until the correct password is found.

Dictionary Attack

Systematically testing a predefined list of words and common passwords against a target.

Rainbow Table

Precomputed table of cryptographic hash values used to speed up password cracking.

Credential Stuffing

Automated injection of stolen pairs of credentials across multiple target sites.

Cross-Site Scripting (XSS)

Injecting malicious scripts into trusted websites viewed by other users.

Stored XSS

Persistent malicious script saved on the server database and delivered to visitors.

Reflected XSS

Non-persistent script reflected off a web server in an immediate HTTP response.

SQL Injection (SQLi)

Injecting malicious SQL statements into web inputs to manipulate backend databases.

Cross-Site Request Forgery

Tricking an authenticated user into running unwanted actions on a trusted web app.

Buffer Overflow

Writing more data to a buffer than it holds, overwriting adjacent memory spaces.

Directory Traversal

Exploiting insufficient validation to browse file directories outside the web root.

Privilege Escalation

Exploiting a bug or misconfiguration to gain unauthorized higher access levels.

Session Hijacking

Stealing or predicting an active session token to take control of an authorized session.

Symmetric Encryption

Cryptographic system using a single shared secret key for encryption and decryption.

Asymmetric Encryption

Public-key cryptography using mathematically paired public and private keys.

AES

Advanced Encryption Standard; widely used symmetric block cipher (128, 192, 256 bits).

DES

Data Encryption Standard; deprecated 56-bit symmetric cipher vulnerable to brute force.

3DES

Triple DES; applies DES three times per block; largely phased out for AES.

RSA

Common asymmetric algorithm based on the difficulty of factoring large prime numbers.

Diffie-Hellman

Key-exchange protocol enabling two parties to negotiate a shared key over insecure links.

ECC

Elliptic Curve Cryptography; provides high-strength asymmetric security with small keys.

Hashing

One-way mathematical function transforming arbitrary inputs into fixed-length digests.

MD5

Message Digest 5; legacy 128-bit hash algorithm compromised by collision attacks.

SHA-1

160-bit hash algorithm deemed insecure due to demonstrated collision vulnerabilities.

SHA-256

A secure 256-bit hashing algorithm member of the SHA-2 family.

Salting

Adding random data to passwords prior to hashing to thwart rainbow table attacks.

Public Key Infrastructure

System of digital certificates, CAs, and policies managing public-key cryptography.

Certificate Authority (CA)

Trusted entity that issues, validates, and revokes digital identity certificates.

Digital Certificate

Electronic document binding an entity's identity to its public key via CA signature.

Certificate Revocation List

List of revoked digital certificates published periodically by a CA.

OCSP

Online Certificate Status Protocol; queries real-time revocation status of certificates.

Digital Signature

Cryptographic proof of message authenticity and integrity using a sender's private key.

Steganography

The practice of concealing covert data or files inside another ordinary file.

Firewall

Network device monitoring and filtering traffic according to defined security rules.

Stateful Firewall

Tracks active connections and filters packets based on state context and established sessions.

Stateless Firewall

Filters individual packets independently based on static rule headers without context.

Next-Gen Firewall (NGFW)

Combines traditional packet inspection with application control, IPS, and DPI.

Web Application Firewall

Specialized firewall that monitors and inspects HTTP/S traffic targeting web services.

Intrusion Detection System

Monitors network traffic for malicious activity and policy breaches, logging alerts.

Intrusion Prevention System

Inline system monitoring traffic to actively detect and automatically block attacks.

Signature-Based Detection

Identifies security threats by comparing traffic directly to known attack signatures.

Heuristic/Anomaly Detection

Identifies threats by flagging significant deviations from a baseline of normal behavior.

Honeypot

Decoy system deliberately isolated and configured to attract and observe attackers.

Honeynet

A decoy network comprised of multiple honeypots used to study attacker methods.

Virtual Private Network

Encrypted tunnel providing secure communication across an insecure public network.

IPsec

Protocol suite providing authentication and encryption of IP packets across networks.

IPsec: AH

Authentication Header; guarantees integrity and origin authentication without encryption.

IPsec: ESP

Encapsulating Security Payload; provides data confidentiality, integrity, and auth.

Demilitarized Zone (DMZ)

Perimeter network subnet isolating public-facing services from an internal network.

Network Address Translation

Translates private, non-routable IP addresses to public routable IPs for internet routing.

VLAN

Virtual Local Area Network; logically isolates broadcast domains within shared switches.

Air Gapping

Physically isolating a secure computer or network from external networks and the web.

Proxy Server

Intermediary server acting on behalf of clients to request resources from other hosts.

Reverse Proxy

Server placed in front of web servers handling caching, SSL termination, and load balancing.

Load Balancer

Distributes incoming network traffic evenly across a farm of redundant backend servers.

NAC

Network Access Control; validates device compliance and health before granting access.

SIEM

Security Information and Event Management; aggregates and analyzes log data centrally.

SOAR

Security Orchestration, Automation, and Response; automates remediation workflows.

Data Loss Prevention (DLP)

Software identifying and preventing unauthorized exfiltration of sensitive organizational data.

Endpoint Detection & Response

Endpoint security tool continuously monitoring hosts to catch and contain advanced threats.

RADIUS

Remote Authentication Dial-In User Service; centralized AAA networking protocol.

TACACS+

Cisco AAA protocol encrypting the entire payload and separating auth and authz.

Kerberos

Network authentication protocol using tickets and symmetric keys to avoid plaintext transit.

Key Distribution Center

Central trusted authentication server in Kerberos composed of an AS and TGS.

LDAP

Lightweight Directory Access Protocol; protocol for querying directory services (port 389).

LDAPS

Secure LDAP encrypted using TLS/SSL over TCP port 636.

Single Sign-On (SSO)

Session authentication process allowing access to multiple apps via one credential set.

SAML

XML-based open standard exchanging authentication and authorization data via SSO.

OAuth 2.0

Open authorization framework granting third-party apps token-based resource access.

OpenID Connect (OIDC)

Identity layer built atop OAuth 2.0 delivering federated single sign-on authentication.

Multi-Factor Authentication

Access control requiring two or more independent credential categories to authenticate.

MFA Factors: Something you know

Authentication factor based on knowledge, such as passwords, PINs, or passphrases.

MFA Factors: Something you have

Authentication factor based on physical possession, such as smart cards or OTP tokens.

MFA Factors: Something you are

Biometric authentication factor such as fingerprints, retina scans, or facial geometry.

MFA Factors: Somewhere you are

Contextual authentication factor based on geographic location, such as IP or GPS.

MFA Factors: Something you do

Behavioral biometric factor such as typing cadence or signature dynamics.

Role-Based Access Control

Access permissions assigned to roles rather than directly to individual users.

Rule-Based Access Control

Access granted or restricted strictly based on global rules, ACLs, and system logic.

Discretionary Access Control

Data owner maintains absolute authority over who can access their files and objects.

Mandatory Access Control

Access determined strictly by fixed labels and clearances assigned by a central admin.

Attribute-Based Access Control

Grants access based on complex policies evaluating user, resource, and environmental attributes.

Least Privilege

Security principle providing users only the bare minimum access needed for their duties.

Separation of Duties

Dividing critical multi-step tasks among multiple workers to prevent fraud and errors.

Zero Trust

Security architecture operating under the assumption that every request must be verified.

Wireless: WEP

Wired Equivalent Privacy; obsolete, easily cracked legacy wireless encryption standard.

Wireless: WPA2

Wi-Fi Protected Access 2; relies on AES encryption and CCMP for robust security.

Wireless: WPA3

Modern Wi-Fi standard replacing PSK with SAE to prevent offline dictionary attacks.

SAE

Simultaneous Authentication of Equals; handshake protocol in WPA3 resisting offline attacks.

Rogue Access Point

An unauthorized wireless access point connected to an enterprise network without permission.

Evil Twin

A fraudulent Wi-Fi AP masquerading as a legitimate network to intercept user traffic.

Deauthentication Attack

Spoofing disconnect frames to kick wireless clients off a network, often to capture handshakes.

Bluejacking

Sending unsolicited text or image messages to Bluetooth-enabled devices nearby.

Bluesnarfing

Unauthorized theft of data, contacts, or texts from a device via a Bluetooth connection.

RFID

Radio Frequency Identification; wireless tech using electromagnetic fields to identify tags.

NFC

Near Field Communication; short-range contactless wireless communications standard.

Incident Response Lifecycle

Phases: Preparation, Detection & Analysis, Containment, Eradication, Recovery, Lessons Learned.

Order of Volatility

Sequence of data preservation prioritizing storage most prone to loss (CPU cache to disk).

Chain of Custody

Chronological documentation tracking the collection, handling, and transfer of legal evidence.

Legal Hold

Directive ordering the preservation of all relevant digital data for impending litigation.

Business Impact Analysis

Process evaluating the operational and financial impact of disruptive disaster events.

RTO

Recovery Time Objective; maximum acceptable timeframe to restore a business process.

RPO

Recovery Point Objective; maximum acceptable data loss measured backwards in time.

MTBF

Mean Time Between Failures; average lifespan expected between hardware system failures.

MTTR

Mean Time to Repair; average duration required to troubleshoot and fix a failed component.

Single Point of Failure

An isolated system component whose individual breakdown halts the entire operation.

RAID 0

Disk striping providing enhanced performance without fault tolerance or redundancy.

RAID 1

Disk mirroring duplicating data across two drives to provide continuous fault tolerance.

RAID 5

Block-level striping with distributed parity, tolerating the failure of a single drive.

Cold Site

Backup recovery location with basic space and power, but lacking hardware and data.

Warm Site

Recovery site equipped with hardware and network links, requiring data restoration to run.

Hot Site

Fully mirrored, continuous duplicate facility ready for instantaneous operational failover.

Differential Backup

Backs up all data altered since the last full backup; recovery requires full plus latest diff.

Incremental Backup

Backs up only data changed since the previous backup; recovery requires full plus every increment.

Vulnerability Assessment

Systematic identification and evaluation of security weaknesses without active exploitation.

Penetration Testing

Authorized, simulated attack executed to actively exploit weaknesses and evaluate defenses.

Black Box Testing

Security testing where the tester has zero prior knowledge of the target environment.

White Box Testing

Security testing conducted with complete structural knowledge and source code access.

Gray Box Testing

Testing conducted with limited, partial knowledge of internal architecture and credentials.

Red Team

Offensive group roleplaying as adversaries attempting to breach defenses.

Blue Team

Defensive security team monitoring systems, analyzing alerts, and repelling attacks.

Purple Team

Collaborative function facilitating real-time feedback between offensive and defensive teams.

Bug Bounty

Rewards offered by organizations to external researchers who discover and report flaws.

OSINT

Open Source Intelligence; gathering intel through publicly available accessible sources.

Port Scanning

Probing open network ports to identify active listening services on a remote host.

CVSS

Common Vulnerability Scoring System; open framework assessing vulnerability severity scores.

CVE

Common Vulnerabilities and Exposures; standardized dictionary of publicly known flaws.

Cloud: IaaS

Infrastructure as a Service; provider offers virtualized compute, storage, and networking.

Cloud: PaaS

Platform as a Service; provider supplies OS and development frameworks; users deploy apps.

Cloud: SaaS

Software as a Service; full application managed and delivered over the web by the vendor.

Public Cloud

Multi-tenant cloud infrastructure owned by a third-party vendor accessible over the internet.

Private Cloud

Cloud environment provisioned for exclusive use by a single individual organization.

Hybrid Cloud

Cloud infrastructure combining distinct public and private platforms bound by technology.

Shared Responsibility Model

Delineates security duties split between a cloud service provider and the customer.

CASB

Cloud Access Security Broker; tool enforcing security policies between users and cloud apps.

Virtualization

Running multiple independent virtual machines simultaneously on a single physical host.

Hypervisor Type 1

Bare-metal hypervisor installed directly onto hardware without an underlying OS.

Hypervisor Type 2

Hosted hypervisor running as software on top of a conventional operating system.

VM Escape

Attack breaking through isolation barriers, allowing code execution on the host OS.

Containerization

OS-level virtualization bundling an app and dependencies sharing the host OS kernel.

Infrastructure as Code (IaC)

Managing and provisioning compute platforms via machine-readable declaration files.

DevSecOps

Integrating security controls directly throughout every phase of the DevOps lifecycle.

Static Code Analysis (SAST)

Analyzing application source code for flaws without executing the underlying program.

Dynamic Code Analysis (DAST)

Testing running software applications from the outside to locate runtime vulnerabilities.

Hardening

The process of securing a system by turning off unused ports, services, and accounts.

Data Sanitization

Permanently erasing or destroying data so it cannot be recovered by any means.

Degaussing

Exposing magnetic media to powerful magnetic fields to irreversibly wipe recorded data.

Purging

Sanitizing data so it cannot be reconstructed even through advanced laboratory methods.

PII

Personally Identifiable Information; any data that can directly identify an individual.

PHI

Protected Health Information; medical and health records protected under privacy rules.

Data Owner

Executive accountable for safeguarding corporate data and determining its classification.

Data Custodian

Technical staff tasked with daily storage, maintenance, and backup of organizational data.

Data Protection Officer (DPO)

Corporate officer ensuring organizational compliance with complex privacy frameworks.

SLA

Service Level Agreement; contract setting defined performance and uptime standards.

MOU

Memorandum of Understanding; non-binding document establishing common intent and goals.

NDA

Non-Disclosure Agreement; legally binding pact restricting unauthorized data sharing.

AUP

Acceptable Use Policy; rules detailing what actions employees can perform on assets.

Shadow IT

Hardware or cloud services deployed within an enterprise without IT knowledge or approval.