CompTIA Security+ Exam Notes

CompTIA Security+ Exam Notes
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Thursday, November 27, 2025

Supply Chain Security Explained: Risks and Strategies Across Software, Hardware, and Services

 Supply Chain Security

Supply chain security refers to protecting the integrity, confidentiality, and availability of components and processes involved in delivering software, hardware, and services. Here’s a breakdown across the three domains:

1. Software Supply Chain Security
This focuses on ensuring that the code and dependencies used in applications are trustworthy and free from malicious alterations.
  • Key Risks:
    • Compromised open-source libraries or third-party packages.
    • Malicious updates or injected code during build processes.
    • Dependency confusion attacks (using similarly named packages).
  • Best Practices:
    • Code Signing: Verify the authenticity of software updates.
    • SBOM (Software Bill of Materials): Maintain a list of all components and dependencies.
    • Secure CI/CD Pipelines: Implement access controls and integrity checks.
    • Regular Vulnerability Scans: Use tools like Snyk or OWASP Dependency-Check.
2. Hardware Supply Chain Security
This involves protecting physical components from tampering or counterfeit risks during manufacturing and distribution.
  • Key Risks:
    • Counterfeit chips or components.
    • Hardware Trojans embedded during production.
    • Interdiction attacks (devices altered in transit).
  • Best Practices:
    • Trusted Suppliers: Source components from verified vendors.
    • Tamper-Evident Packaging: Detect unauthorized access during shipping.
    • Component Traceability: Track origin and movement of parts.
    • Firmware Integrity Checks: Validate firmware before deployment.
3. Service Provider Supply Chain Security
This applies to third-party vendors offering cloud, SaaS, or managed services.
  • Key Risks:
    • Insider threats at service providers.
    • Misconfigured cloud environments.
    • Dependency on providers with a weak security posture.
  • Best Practices:
    • Vendor Risk Assessments: Evaluate security policies and compliance.
    • Shared Responsibility Model: Understand which security tasks are yours and which are the provider’s.
    • Continuous Monitoring: Use tools for real-time threat detection.
    • Contractual Security Clauses: Include SLAs for incident response and data protection.
Why It Matters: A single weak link in the supply chain can compromise entire ecosystems. Attacks like SolarWinds (software) and counterfeit chip scandals (hardware) show how devastating these breaches can be.

Wednesday, November 26, 2025

OWASP Security Testing Guide Explained: A Complete Overview

 OWASP Security Testing Guide (WSTG)

The OWASP Security Testing Guide (WSTG) is a comprehensive framework developed by the Open Web Application Security Project (OWASP) to help security professionals systematically test web applications and services for vulnerabilities. Here’s a detailed explanation:

1. What is the OWASP Security Testing Guide?
The OWASP WSTG is an open-source, community-driven resource that provides best practices, methodologies, and test cases for assessing the security of web applications. It is widely used by penetration testers, developers, and organizations to ensure robust application security.
It focuses on identifying weaknesses in areas such as:
  • Authentication
  • Session management
  • Input validation
  • Configuration management
  • Business logic
  • Cryptography
  • Client-side security
2. Objectives
  • Standardization: Provide a consistent methodology for web application security testing.
  • Comprehensive Coverage: Address all major security risks, including those in the OWASP Top 10.
  • Education: Help developers and testers understand vulnerabilities and how to prevent them.
3. Testing Methodology
The guide follows a structured approach:
  • Information Gathering: Collect details about the application, technologies, and architecture.
  • Configuration & Deployment Testing: Check for misconfigurations and insecure setups.
  • Authentication & Session Testing: Validate login mechanisms, password policies, and session handling.
  • Input Validation Testing: Detect vulnerabilities like SQL Injection, XSS, and CSRF.
  • Error Handling & Logging: Ensure proper error messages and secure logging.
  • Cryptography Testing: Verify encryption and key management practices.
  • Business Logic Testing: Identify flaws in workflows that attackers could exploit.
  • Client-Side Testing: Assess JavaScript, DOM manipulation, and browser-side security.
4. Key Features
  • Open Source: Freely available and maintained by a global community.
  • Versioned Framework: Current stable release is v4.2, with v5.0 in development.
  • Scenario-Based Testing: Each test case is identified by a unique code (e.g., WSTG-INFO-02).
  • Integration with SDLC: Encourages security testing throughout the development lifecycle.
5. Tools Commonly Used
  • OWASP ZAP (Zed Attack Proxy)
  • Burp Suite
  • Nmap
  • Metasploit
6. Benefits
  • Improves application security posture.
  • Reduces risk of data breaches.
  • Aligns with compliance standards (PCI DSS, ISO 27001, NIST).
  • Supports DevSecOps and CI/CD integration for continuous security testing.
7. Best Practices
  • Always obtain proper authorization before testing.
  • Use dedicated testing environments.
  • Document all findings and remediation steps.
  • Prioritize vulnerabilities based on risk and impact.

Understanding the Order of Volatility in Digital Forensics

 Order of Volatility

The order of volatility is a concept in digital forensics that determines the sequence in which evidence should be collected from a system during an investigation. It prioritizes data based on how quickly it can be lost or changed when a system is powered off or continues running.

Why It Matters
Digital evidence is fragile. Some data resides in memory and disappears instantly when power is lost, while other data persists on disk for years. Collecting evidence out of order can result in losing critical information.

General Principle
The rule is:
Collect the most volatile (short-lived) data first, then move to less volatile (long-lived) data.

Typical Order of Volatility
From most volatile to least volatile:
1. CPU Registers, Cache
  • Extremely short-lived; lost immediately when power is off.
  • Includes processor state and cache contents.
2. RAM (System Memory)
  • Contains running processes, network connections, encryption keys, and temporary data.
  • Lost when the system shuts down.
3. Network Connections & Routing Tables
  • Active sessions and transient network data.
  • Changes rapidly as connections open/close.
4. Running Processes
  • Information about currently executing programs.
5. System State Information
  • Includes kernel tables, ARP cache, and temporary OS data.
6. Temporary Files
  • Swap files, page files, and other transient storage.
7. Disk Data
  • Files stored on hard drives or SSDs.
  • Persistent until deleted or overwritten.
8. Remote Logs & Backups
  • Logs stored on remote servers or cloud systems.
  • Usually stable and long-lived.
9. Archive Media
  • Tapes, optical disks, and offline backups.
  • Least volatile; can last for years.
Key Considerations
  • Live Acquisition: If the system is running, start with volatile data (RAM, network).
  • Forensic Soundness: Use write-blockers and hashing to maintain integrity.
  • Legal Compliance: Follow chain-of-custody procedures.

Tuesday, November 25, 2025

How to Stop Google from Using Your Emails to Train AI

Disable Google's Smart Feature

Google is scanning your email messages and attachments to train its AI. This video shows you the steps to disable that feature.

Zero Touch Provisioning (ZTP): How It Works, Benefits, and Challenges

 Zero Touch Provisioning (ZTP)

Zero Touch Provisioning (ZTP) is a network automation technique that allows devices, such as routers, switches, or servers, to be configured and deployed automatically without manual intervention. Here’s a detailed breakdown:

1. What is Zero Touch Provisioning?
ZTP is a process where new network devices are automatically discovered, configured, and integrated into the network as soon as they are powered on and connected. It eliminates the need for administrators to manually log in and configure each device, which is especially useful in large-scale deployments.

2. How It Works
The ZTP workflow typically involves these steps:

Initial Boot:
When a device is powered on for the first time, it has a minimal factory-default configuration.

DHCP Discovery:
The device sends a DHCP request to obtain:
  • An IP address
  • The location of the provisioning server (via DHCP options)
Download Configuration/Script:
The device contacts the provisioning server (often via HTTP, HTTPS, FTP, or TFTP) and downloads:
  • A configuration file
  • Or a script that applies the configuration
Apply Configuration:
The device executes the script or applies the configuration, which may include:
  • Network settings
  • Security policies
  • Firmware updates
Validation & Registration:
The device validates the configuration and registers itself with the network management system.

3. Key Components
  • Provisioning Server: Stores configuration templates and scripts.
  • DHCP Server: Provides IP and provisioning server details.
  • Automation Tools: Tools like Ansible, Puppet, or vendor-specific solutions (Cisco DNA Center, Juniper ZTP).
  • Security Mechanisms: Authentication and encryption to prevent unauthorized provisioning.
4. Benefits
  • Scalability: Deploy hundreds or thousands of devices quickly.
  • Consistency: Ensures uniform configurations across devices.
  • Reduced Errors: Minimizes human error during manual setup.
  • Cost Efficiency: Saves time and operational costs.
5. Use Cases
  • Large enterprise networks
  • Data centers
  • Branch office deployments
  • IoT device onboarding
6. Challenges
  • Security Risks: If not properly secured, attackers could inject malicious configurations.
  • Network Dependency: Requires DHCP and connectivity to provisioning servers.
  • Vendor Lock-In: Some ZTP solutions are vendor-specific.

Saturday, November 1, 2025

DTLS vs TLS: Key Differences and Use Cases

 DTLS (Datagram Transport Layer Security)

Datagram Transport Layer Security (DTLS) is a protocol that provides privacy, integrity, and authenticity for datagram-based communications. It’s essentially a version of TLS (Transport Layer Security) adapted for use over UDP (User Datagram Protocol), which is connectionless and doesn’t guarantee delivery, order, or protection against duplication.

Here’s a detailed breakdown of DTLS:

1. Purpose of DTLS
DTLS secures communication over unreliable transport protocols like UDP. It’s used in applications where low latency is crucial, such as:
  • VoIP (Voice over IP)
  • Online gaming
  • Video conferencing
  • VPNs (e.g., OpenVPN)
  • IoT communications
2. Key Features
Encryption: Protects data from eavesdropping.
Authentication: Verifies the identity of communicating parties.
Integrity: Ensures data hasn’t been tampered with.
Replay Protection: Prevents attackers from reusing captured packets.

3. DTLS vs TLS


4. How DTLS Works
A. Handshake Process
  • Similar to TLS: uses asymmetric cryptography to establish a shared secret.
  • Includes mechanisms to handle packet loss, reordering, and duplication.
  • Uses sequence numbers and retransmission timers.
B. Record Layer
  • Encrypts and authenticates application data.
  • Adds headers for fragmentation and reassembly.
C. Alert Protocol
  • Communicates errors and session termination.
5. DTLS Versions
  • DTLS 1.0: Based on TLS 1.1.
  • DTLS 1.2: Based on TLS 1.2, widely used.
  • DTLS 1.3: Based on TLS 1.3, it is more efficient and secure, but less widely adopted.
6. Security Considerations
  • DTLS must handle DoS attacks because UDP lacks a connection state.
  • Uses stateless cookies during handshake to mitigate resource exhaustion.
  • Vulnerable to amplification attacks if not correctly configured.
7. Applications
WebRTC: Real-time communication in browsers.
CoAP (Constrained Application Protocol): Used in IoT.
VPNs: OpenVPN can use DTLS for secure tunneling.

HTML Scraping for Penetration Testing: Techniques, Tools, and Ethical Practices

 HTML Scraping

HTML scraping is the process of extracting and analyzing the HTML content of a web page to uncover hidden elements, understand the structure, and identify potential security issues. Here's a detailed breakdown:

1. What Is HTML Scraping?
HTML scraping involves programmatically or manually inspecting a web page's HTML source code to extract information. In penetration testing, it's used to discover hidden form fields, parameters, or other elements that may not be visible in the rendered page but could be manipulated.

2. Why Use HTML Scraping in Penetration Testing?
  • Identify Hidden Inputs: Hidden fields may contain sensitive data like session tokens, user roles, or flags.
  • Reveal Client-Side Logic: JavaScript embedded in the page may expose logic or endpoints.
  • Discover Unlinked Resources: URLs or endpoints not visible in the UI may be found in the HTML.
  • Understand Form Structure: Helps in crafting payloads for injection attacks (e.g., SQLi, XSS).
3. Techniques for HTML Scraping
Manual Inspection
  • Use browser developer tools (F12 or right-click → Inspect).
  • Look for <input type="hidden">, JavaScript variables, or comments.
  • Check for form actions, method types (GET/POST), and field names.
Automated Tools
  • Burp Suite: Intercepts and analyzes HTML responses.
  • OWASP ZAP: Scans and spiders web apps to extract HTML.
  • Custom Scripts: Use Python with libraries like BeautifulSoup or Selenium.
Example using Python:


4. What to Look For
  • Hidden form fields
  • CSRF tokens
  • Session identifiers
  • Default values
  • Unusual parameters
  • Commented-out code or debug info
5. Ethical Considerations
  • Always have authorization before scraping or testing a web application.
  • Respect robots.txt and terms of service when scraping public sites.
  • Avoid scraping personal or sensitive data unless explicitly permitted.