OWASP Top 10 (2025): A Practical Application Security Perspective
If you spend even a short time in cybersecurity, one term comes up again and again: OWASP Top 10. From training materials to real-world security assessments, it quickly becomes a familiar reference. For many people entering cybersecurity, OWASP Top 10 is often the first security framework they learn. Over time, it becomes a common language shared by developers, security testers, auditors, and compliance teams. As OWASP continues to update the Top 10 based on real-world vulnerability data, I felt this was a good place to start my writing journey on Medium. This article looks at the OWASP Top 10 (2025) from a practical application security perspective, focusing on how each category is commonly understood and validated during security testing and audits. We'll start with a brief overview of OWASP and why the OWASP Top 10 matters, and then walk through each category with practical context.
What Is OWASP? The Open Worldwide Application Security Project (OWASP) is a global, non-profit organization focused on improving the security of software applications. OWASP provides free and open resources, including documentation, tools, and frameworks, to help organizations understand and reduce security risks. One of its most widely adopted publications is the OWASP Top 10, which identifies the most critical web application security risks based on real-world data collected from security professionals worldwide.
Why the OWASP Top 10 Matters to Organizations From an organizational and risk-management perspective, the OWASP Top 10 matters because it: Highlights security risks that are commonly exploited in real environments
Helps organizations prioritize security efforts based on impact
Provides a shared language for developers, security teams, and auditors
Is widely referenced in security assessments, audits, and compliance programs
Most importantly, the OWASP Top 10 acts as a baseline for application security.
OWASP Top 10 (2025): Practical Breakdown A01: Broken Access Control What Is Broken Access Control? Broken Access Control occurs when an application does not correctly enforce what an authenticated user is allowed to do. As a result, users may access resources or perform actions beyond their intended permissions. In security assessments, this category consistently appears as one of the most frequently identified and most impactful risks. Why It Matters! Failures in access control can lead to: Unauthorized access to sensitive data Privilege escalation Account abuse and data manipulation Compliance and regulatory impact These issues are especially critical because they often require no advanced exploitation techniques—only normal application behavior.
How Broken Access Control Commonly Exists in Applications In real-world applications, access control failures usually stem from design and implementation gaps such as: Authorization checks enforced only in frontend components
APIs trusting user-supplied identifiers or roles
Missing object-level permission validation
Inconsistent access rules across similar endpoints
Assumptions that authenticated users are inherently trusted
These weaknesses often go unnoticed because authentication works correctly, creating a false sense of security.
How It Is Identified During Testing During security testing and audits, broken access control is typically identified through logical and behavioral validation rather than complex payloads. Common approaches include: Attempting restricted actions using lower-privileged accounts
Accessing sensitive endpoints directly, bypassing the user interface
Modifying object identifiers to test ownership validation
Comparing authorization behavior across different user roles
Reviewing consistency of access enforcement across APIs and features
The primary goal is to confirm that authorization is enforced server-side and consistently, regardless of how the request is initiated. Key Takeaway Broken Access Control is rarely a tooling issue. It is most often caused by missing, inconsistent, or implicit authorization logic.
A02: Security Misconfiguration What Is Security Misconfiguration? Security Misconfiguration occurs when systems, applications, or services are not securely configured, hardened, or maintained. This includes insecure default settings, unnecessary features enabled, or excessive permissions.
Why It Matters! Security misconfigurations can: Expose sensitive data Provide attackers with easy entry points Undermine otherwise secure applications Lead to large-scale breaches Many real-world incidents start with one small configuration oversight.
How Security Misconfiguration Commonly Exists in Applications In practice, misconfigurations often appear as: Default credentials or settings left unchanged Debug or verbose error messages enabled in production Unnecessary services or ports exposed Overly permissive cloud or network configurations Inconsistent security settings across environments These issues are usually introduced during deployment or rapid changes.
How It Is Identified During Testing Validation typically includes: Reviewing application, server, and cloud configurations Identifying exposed services or management interfaces Triggering error conditions to check information disclosure Comparing configurations across environments Verifying adherence to hardened baseline standards Key Takeaway Security Misconfiguration is less about attackers and more about operational discipline. Secure configurations must be intentional, documented, and repeatable.
A03: Software Supply Chain Failures What Are Software Supply Chain Failures? Software Supply Chain Failures occur when vulnerabilities are introduced through third-party components, dependencies, or build processes that are not properly controlled or verified.
Why It Matters! Modern applications rely heavily on external components. A single vulnerable or compromised dependency can impact the entire system.
How Supply Chain Failures Commonly Exist In real environments, this risk commonly appears as: Outdated libraries with known vulnerabilities No inventory of third-party components Blind trust in open-source packages Insecure or uncontrolled CI/CD pipelines Lack of integrity checks for build artifacts These risks often remain invisible until an incident occurs.
How It Is Identified During Assessments Validation typically includes: Reviewing dependency lists and versions Identifying known vulnerabilities in third-party components Assessing CI/CD pipeline access and controls Evaluating update and patch management processes Verifying integrity controls for build and deployment artifacts
Key Takeaway If an organization cannot clearly identify and control its dependencies, it cannot fully trust its application.
A04: Cryptographic Failures What Are Cryptographic Failures? Cryptographic Failures occur when sensitive data is not properly protected through encryption or cryptographic controls, either in transit or at rest.
Why It Matters! Weak or inconsistent cryptographic practices can lead to: Credential exposure Data leakage Session compromise Regulatory non-compliance These failures often remain unnoticed until data is compromised.
How Cryptographic Failures Commonly Exist In real-world applications, this category often includes: Sensitive data stored without encryption Weak or outdated cryptographic algorithms Improper handling of secrets and keys Missing or misconfigured transport encryption Insecure cookie or token protection The issue is usually misuse, not absence, of cryptography.
How It Is Identified During Reviews Teams typically: Inspect how sensitive data is stored and transmitted Review encryption standards and configurations Examine key and secret management practices Check token and cookie protection settings Validate enforcement of secure transport mechanisms Key Takeaway Cryptography must be applied correctly and consistently. Using encryption incorrectly provides little real protection.
A05: Injection What Is Injection? Injection vulnerabilities occur when untrusted input is processed as commands or queries by an application. This includes, but is not limited to, SQL injection.
Why It Matters! Injection flaws can allow attackers to: Access or modify data Bypass authentication or authorization Execute unintended commands Despite being well-known, injection remains a persistent risk.
How Injection Commonly Exists in Applications Injection issues often arise from: Dynamic query construction using user input
Lack of input validation
Insecure use of interpreters or templates
Assumptions that internal inputs are safe
Inconsistent secure coding practices
Injection risks now extend beyond traditional databases.
How It Is Identified During Testing Validation usually includes: Submitting unexpected or malformed input Observing application responses and error handling
Reviewing query construction methods
Verifying use of safe APIs and parameterized queries
Identifying inconsistent input handling across components Key Takeaway Injection vulnerabilities are a direct result of trusting input too much. Every external input should be treated as untrusted by default.
To be continued…