Cyber Security Cheat Sheet

Security Fundamentals

Concept	Definition	Example
CIA Triad	Confidentiality, Integrity, Availability	Encryption for confidentiality, checksums for integrity, redundancy for availability
Defense in Depth	Multiple layers of security controls	Firewall + IDS + encryption + access controls
Principle of Least Privilege	Users get minimum access needed	Database user only gets read access if that's all they need
Zero Trust	Never trust, always verify	Continuous authentication and authorization checks
Threat Modeling	Identifying potential security threats	STRIDE model: Spoofing, Tampering, Repudiation, Information disclosure, Denial of service, Elevation of privilege

Common Attack Types

Attack	Description	Defense
SQL Injection	Injecting malicious SQL code	Input validation, parameterized queries, least privilege
Cross-Site Scripting (XSS)	Injecting malicious scripts into web pages	Input sanitization, output encoding, CSP headers
Cross-Site Request Forgery (CSRF)	Tricking users to execute unwanted actions	CSRF tokens, same-site cookies, origin headers
Man-in-the-Middle	Intercepting communications	Encryption, certificate validation, VPNs
Phishing	Tricking users to reveal sensitive info	Security awareness training, email filtering, MFA
Denial of Service (DoS)	Overwhelming systems to deny service	Rate limiting, traffic filtering, redundancy
Buffer Overflow	Writing beyond buffer boundaries	Bounds checking, safe coding practices, ASLR
Ransomware	Encrypting data and demanding payment	Regular backups, endpoint protection, user training

Authentication & Authorization

Method	Description	Advantages/Disadvantages
Passwords	Something you know	Easy to implement, vulnerable to brute force
Multi-Factor Authentication (MFA)	Multiple verification factors	More secure, can be inconvenient
Biometrics	Something you are (fingerprint, face)	Difficult to forge, privacy concerns
Single Sign-On (SSO)	One login for multiple systems	Convenience, centralized control
OAuth	Authorization framework	Delegated access, token-based
OpenID Connect	Authentication layer on OAuth	Standardized identity, token validation
Role-Based Access Control (RBAC)	Permissions based on roles	Scalable, manageable access control
Mandatory Access Control (MAC)	System-enforced access control	High security, less flexible

Cryptography

Type	Algorithm	Use Case	Key Size
Symmetric Encryption	AES	Data encryption	128, 192, 256 bits
Symmetric Encryption	3DES	Legacy systems	112, 168 bits
Asymmetric Encryption	RSA	Key exchange, digital signatures	2048, 3072, 4096 bits
Asymmetric Encryption	ECC	Mobile, IoT devices	256, 384, 521 bits
Hash Function	SHA-256	Integrity verification	256 bits
Hash Function	SHA-3	Future-proof hashing	224, 256, 384, 512 bits
Hash Function	MD5	Deprecated	128 bits
Key Exchange	Diffie-Hellman	Secure key exchange	2048+ bits

Network Security

Technology	Purpose	Implementation
Firewall	Filter network traffic	Rule-based packet filtering
VPN	Secure remote access	IPSec, SSL/TLS tunneling
Intrusion Detection System (IDS)	Detect suspicious activity	Signature-based, anomaly-based
Intrusion Prevention System (IPS)	Block detected threats	Inline traffic inspection
Network Segmentation	Isolate network sections	VLANs, subnetting, microsegmentation
SIEM	Security information and event management	Log aggregation, correlation, analysis
DMZ	Isolated network for public services	Web servers, email servers
Port Security	Control access to network ports	MAC address filtering

Security Protocols

Protocol	Layer	Purpose	Security Feature
SSL/TLS	Transport	Secure communication	Encryption, authentication
IPSec	Network	Secure IP communication	Authentication, encryption, integrity
SSH	Application	Secure remote access	Encrypted shell access
SFTP	Application	Secure file transfer	SSH-based file transfer
HTTPS	Application	Secure web communication	HTTP over TLS
WPA3	Network	Secure WiFi	Individualized data encryption
Kerberos	Application	Network authentication	Trusted third-party authentication
SAML	Application	Single sign-on	Security assertion markup language

Vulnerability Management

Process	Description	Tools
Vulnerability Scanning	Systematic search for security weaknesses	Nessus, OpenVAS, Qualys
Penetration Testing	Simulated attacks to find vulnerabilities	Metasploit, Burp Suite, Nmap
Risk Assessment	Evaluate potential security risks	CVSS, DREAD, OCTAVE
Asset Management	Track and manage security of assets	CMDB, asset discovery tools
Patch Management	Manage software updates and patches	WSUS, Red Hat Satellite, Ansible
Security Auditing	Systematic evaluation of security controls	Compliance tools, configuration checkers

Incident Response

Phase	Activities	Tools
Preparation	Develop IR plan, train staff, establish communication	IR plans, communication tools, training materials
Identification	Detect and analyze security incidents	SIEM, IDS, forensic tools
Containment	Limit the scope of the incident	Network isolation, access controls
Eradication	Remove the cause of the incident	Antivirus, patching, system restoration
Recovery	Restore systems and services	Backups, system monitoring
Lessons Learned	Document and analyze the incident	Documentation, metrics, process improvement

Security Frameworks & Compliance

Framework	Purpose	Key Components
NIST Cybersecurity Framework	Manage cybersecurity risks	Identify, Protect, Detect, Respond, Recover
ISO 27001	Information security management	ISMS, risk management, controls
COBIT	IT governance and management	Process model, maturity model, metrics
PCI DSS	Payment card industry security	Cardholder data protection, network security
SOX	Financial reporting accuracy	Internal controls, audit requirements
HIPAA	Health information privacy	Privacy rule, security rule, breach notification
GDPR	Data protection and privacy	Consent, rights of data subjects, breach reporting

Security Tools

Category	Tool	Function
Network Scanning	Nmap	Port scanning, network discovery
Web Application Testing	Burp Suite	Web vulnerability assessment
Exploitation Framework	Metasploit	Penetration testing, exploit development
Packet Analysis	Wireshark	Network protocol analysis
Vulnerability Scanner	Nessus	Automated vulnerability detection
Forensic Analysis	Autopsy	Digital forensics and investigation
Password Cracking	John the Ripper	Password recovery and testing
System Monitoring	Sysmon	System activity monitoring

Secure Coding Practices

Practice	Description	Implementation
Input Validation	Validate all user inputs	Whitelist validation, parameterized queries
Output Encoding	Encode data for proper context	HTML encoding, URL encoding
Error Handling	Don't leak system information	Generic error messages, logging
Authentication	Implement strong authentication	MFA, secure session management
Authorization	Verify access rights	Role-based access, principle of least privilege
Session Management	Secure session handling	Secure cookies, session timeout
Cryptography	Use strong encryption	Standard algorithms, proper key management
Secure Configuration	Follow security best practices	Remove default accounts, disable unnecessary services

Emerging Security Technologies

Technology	Application	Security Benefits
Zero Trust Architecture	Network security model	Continuous verification, micro-segmentation
Deception Technology	Attack detection and response	Early detection, attacker engagement
Behavioral Analytics	User and entity behavior analysis	Threat detection, anomaly identification
Security Orchestration	Automate security operations	Efficiency, consistency, scalability
Threat Intelligence	Proactive threat detection	Context, indicators of compromise
Blockchain Security	Distributed ledger security	Immutability, transparency, decentralization
Cloud Security	Secure cloud environments	Encryption, identity management, compliance