Zero Trust is a security concept based on the principle:
"Never trust, always verify."
Unlike traditional security models that automatically trust internal network traffic, Zero Trust assumes that every user, device, and application must be authenticated, authorized, and continuously monitored — regardless of whether they are inside or outside the network perimeter.
Verification over Trust
No one is trusted by default — every user, device, and service must prove who they are.
Least Privilege Access
Users and services only get the minimum access they truly need — nothing more.
Continuous Validation
Trust is not permanent — it’s reevaluated continuously (based on behavior, location, device status, etc.).
Micro-Segmentation
The network is divided into small, isolated zones to prevent lateral movement if an attacker breaks in.
Centralized Visibility & Logging
Every access attempt is logged and monitored — critical for audits, compliance, and detecting threats.
Multi-Factor Authentication (MFA)
Identity & Access Management (IAM)
Device Posture Checks (e.g., antivirus, patch status)
ZTNA (Zero Trust Network Access) as a VPN replacement
Micro-segmentation via cloud firewalls or SDN
Security Monitoring Tools (e.g., SIEM, UEBA)
Remote Work: Employees work from anywhere — not just inside a "trusted" office LAN.
Cloud & SaaS adoption: Data lives outside your data center.
Evolving Threat Landscape: Ransomware, insider threats, social engineering.
Without Zero Trust:
A user logs in via VPN and has full network access, just because they're "inside".
With Zero Trust:
The user must verify identity, device health is checked, and access is limited to only necessary apps — no blind trust.
Zero Trust is not a single product — it's a security strategy. Its goal is to reduce risk by enforcing continuous verification and minimizing access. When done right, it can drastically lower the chances of data breaches, insider threats, and lateral movement within a network.
Least Privilege is a fundamental principle in IT and information security. It means:
Every user, system, or process should be granted only the minimum level of access necessary to perform its duties—no more, no less.
The principle of least privilege helps to:
Minimize security risks: If an attacker compromises an account, they can only access what that account is permitted to.
Prevent accidental errors: Users can’t unintentionally change critical systems or data if they don’t have access to them.
Meet compliance requirements: Many standards (e.g., ISO 27001, GDPR) require access control based on the least-privilege model.
An accountant has access to financial systems but not to server configurations.
A web server process can write only in its own directory, not in system folders.
An intern has read-only access to a project folder but cannot modify files.
Role-Based Access Control (RBAC)
Separation of admin and user accounts
Time-limited permissions
Regular access reviews and audits
Directory Traversal (also known as Path Traversal) is a security vulnerability in web applications that allows an attacker to access files or directories outside the intended directory. The attacker manipulates file paths to navigate through the server’s filesystem.
A vulnerable web application often processes file paths directly from user input, such as an URL:
https://example.com/getFile?file=report.pdfIf the server does not properly validate the input, an attacker could modify it like this:
https://example.com/getFile?file=../../../../etc/passwdHere, the attacker uses ../ (parent directory notation) to move up the directory structure and access system files like /etc/passwd (on Linux).
A Bearer Token is a type of access token used for authentication and authorization in web applications and APIs. The term "Bearer" means "holder," which implies that anyone in possession of the token can access protected resources—without additional verification.
Authorization: Bearer <token>.GET /protected-data HTTP/1.1
Host: api.example.com
Authorization: Bearer abcdef123456💡 Tip: To enhance security, use short-lived tokens and transmit them only over HTTPS.
OAuth (Open Authorization) is an open standard protocol for authorization that allows applications to access a user's resources without knowing their credentials (e.g., password). It is commonly used for Single Sign-On (SSO) and API access.
OAuth operates using tokens, which allow an application to access a user's data on their behalf. The typical flow is as follows:
CORS (Cross-Origin Resource Sharing) is a security mechanism implemented by web browsers to control which websites can access resources from other domains. By default, browsers block cross-origin requests—requests made from one website to another domain, protocol, or port—for security reasons.
Without CORS, malicious websites could secretly send requests to other servers (e.g., API servers or banking sites), potentially stealing or misusing sensitive data (Cross-Site Request Forgery, CSRF). CORS ensures that only explicitly allowed websites can access resources.
When a web application makes a cross-origin request (e.g., from http://example.com to https://api.example.com), the browser automatically sends a CORS request. The server must then respond with specific HTTP headers to indicate whether the request is allowed:
Without CORS headers:
The browser blocks the request.
With CORS headers:
The server can respond with Access-Control-Allow-Origin: * (allowing all domains) or a specific domain (Access-Control-Allow-Origin: https://example.com). This enables access.
For certain requests (e.g., PUT, DELETE, or requests with custom headers), the browser sends a preflight request using the OPTIONS method. The server must respond with the correct CORS headers to allow the main request.
CORS is a crucial security measure that prevents unauthorized websites from accessing foreign resources. Developers must configure the correct server-side headers to allow legitimate clients to access the data.
Dynamic HTML (DHTML) is a combination of technologies used to create interactive and dynamic web content. It’s not a standalone standard or programming language but rather a collection of techniques and tools that work together. DHTML enables websites to update content dynamically and provide interactivity without reloading the entire page.
HTML (Hypertext Markup Language)
Provides the basic structure of the webpage.
CSS (Cascading Style Sheets)
Controls the appearance and layout of the webpage. CSS can be dynamically altered to create effects like hover states or style changes.
JavaScript
Adds interactivity and dynamic behavior, such as updating content without a page reload.
DOM (Document Object Model)
A programming interface that allows access to and manipulation of the webpage’s structure. JavaScript interacts with the DOM to change content or add new elements.
Here’s a simple example of a button changing text dynamically:
<!DOCTYPE html>
<html>
<head>
<style>
#text {
color: blue;
font-size: 20px;
}
</style>
<script>
function changeText() {
document.getElementById("text").innerHTML = "Text changed!";
document.getElementById("text").style.color = "red";
}
</script>
</head>
<body>
<p id="text">Original text</p>
<button onclick="changeText()">Click me</button>
</body>
</html>Nowadays, DHTML has been largely replaced by modern techniques like AJAX and frameworks (e.g., React, Vue.js). However, it was a crucial step in the evolution of interactive web applications.
SonarQube is an open-source tool for continuous code analysis and quality assurance. It helps developers and teams evaluate code quality, identify vulnerabilities, and promote best practices in software development.
Code Quality Assessment:
Detecting Security Vulnerabilities:
Technical Debt Evaluation:
Multi-Language Support:
Reports and Dashboards:
SonarQube is available in a free Community Edition and commercial editions with advanced features (e.g., for larger teams or specialized security analysis).
Renovate is an open-source tool that automates the process of updating dependencies in software projects. It continuously monitors your project’s dependencies, including npm, Maven, Docker, and many others, and creates pull requests to update outdated packages, ensuring that your project stays up-to-date and secure.
Key features include:
Renovate helps to reduce technical debt by keeping dependencies current and minimizes the risk of security vulnerabilities in third-party code. It’s popular among developers using platforms like GitHub, GitLab, and Bitbucket.
GitHub Copilot is an AI-powered code assistant developed by GitHub in collaboration with OpenAI. It uses machine learning to assist developers by generating code suggestions in real-time directly within their development environment. Copilot is designed to boost productivity by automatically suggesting code snippets, functions, and even entire algorithms based on the context and input provided by the developer.
GitHub Copilot is built on a machine learning model called Codex, developed by OpenAI. Codex is trained on billions of lines of publicly available code, allowing it to understand and apply various programming concepts. Copilot’s suggestions are based on comments, function names, and the context of the file the developer is currently working on.
GitHub Copilot is available as a paid service, with a free trial period and discounted options for students and open-source developers.
GitHub Copilot has the potential to significantly change how developers work, but it should be seen as an assistant rather than a replacement for careful coding practices and understanding.
Google Apps Script
