Software Testing - Security Testing – Finding Security Vulnerabilities

What is Security Testing?

Security Testing is a type of software testing that focuses on identifying security weaknesses, threats, and vulnerabilities in an application or system. Its main purpose is to ensure that the software protects data, maintains confidentiality, and prevents unauthorized access or misuse.

In simple terms, security testing checks whether a system is safe from hackers, attackers, and malicious users. It verifies that only authorized users can access the system and that sensitive information such as passwords, personal details, and financial data remains secure.

Why is Security Testing Important?

Security testing is essential because modern applications store and process large amounts of sensitive data. If security is weak, attackers can exploit the system and cause serious damage.

Security testing helps to:

  • Protect user data from theft or leakage

  • Prevent hacking, fraud, and cyber attacks

  • Maintain user trust and company reputation

  • Avoid financial losses and legal penalties

  • Ensure compliance with security standards and regulations

Without proper security testing, even a well-functioning application can become dangerous to users and organizations.

What are Security Vulnerabilities?

A security vulnerability is a weakness or flaw in a system that can be exploited by attackers to gain unauthorized access or cause harm.

Common security vulnerabilities include:

  • Weak or predictable passwords

  • Missing authentication or authorization checks

  • Improper input validation

  • Unencrypted sensitive data

  • Poor session management

  • Incorrect access control

Security testing aims to detect these vulnerabilities before the application is released.

Objectives of Security Testing

The main objectives of security testing are:

  1. Confidentiality – Ensure that sensitive data is accessible only to authorized users

  2. Integrity – Ensure that data cannot be modified by unauthorized users

  3. Authentication – Verify that users are who they claim to be

  4. Authorization – Ensure users can access only permitted resources

  5. Availability – Ensure the system remains accessible even during attacks

  6. Non-repudiation – Ensure actions performed in the system can be traced

What Does Security Testing Verify?

Security testing verifies whether the application:

  • Blocks unauthorized access

  • Handles login, logout, and sessions securely

  • Protects sensitive data using encryption

  • Rejects invalid or malicious inputs

  • Logs security-related activities

  • Recovers safely after security failures

Types of Security Testing (Detailed Explanation)

  1. Vulnerability Scanning
    This involves using automated tools to scan the system for known security weaknesses such as outdated libraries, open ports, or misconfigurations.

  2. Penetration Testing
    In this method, testers simulate real-world attacks to identify how an attacker could break into the system. It helps understand the actual risk level of vulnerabilities.

  3. Authentication Testing
    This checks login functionality, password rules, OTP validation, session timeout, and logout behavior to ensure secure user identity verification.

  4. Authorization Testing
    This ensures users cannot access data or features beyond their assigned roles. For example, a normal user should not access admin functions.

  5. Input Validation Testing
    This verifies that the system properly handles invalid or malicious input and does not execute harmful commands.

  6. Security Configuration Testing
    This checks whether servers, databases, and applications are configured securely and follow best security practices.

  7. Session Management Testing
    This ensures sessions expire correctly and cannot be hijacked or reused by attackers.

Real-World Example

Consider an online banking application:

  • If anyone can access another user’s account, it is a security flaw

  • If passwords are stored without encryption, it is a vulnerability

  • If attackers can transfer money without authorization, security testing has failed

Security testing identifies these issues early and helps developers fix them before users are affected.

Advantages of Security Testing

  • Detects hidden security flaws early

  • Protects sensitive and confidential information

  • Reduces risk of cyber attacks

  • Improves system reliability and stability

  • Enhances customer confidence and trust

Consequences of Not Performing Security Testing

If security testing is ignored, the system may face:

  • Data breaches

  • Financial losses

  • Legal consequences

  • Damage to brand reputation

  • Loss of customer trust