Understanding the OWASP Top 10 Security Vulnerabilities

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What is OWASP?

The Open Web Application Security Project (OWASP) is an online community dedicated to web application security. This platform offers valuable resources including articles, documentation, methodologies, and tools focused on protecting applications from security threats.

What is the OWASP Top 10?

The OWASP Top 10 represents a comprehensive report identifying the most critical application security risks. This consensus-driven document examines each vulnerability’s potential risks, impacts, and recommended countermeasures. The report serves two primary purposes: providing organizations with detailed insights into application security challenges and helping enterprises implement effective security practices to minimize risk.

OWASP Top 10: 2025 Edition

The 2025 release candidate was published on November 6, 2025, marking the eighth installment of this critical security framework. This edition shifts focus from isolated code flaws to systemic weaknesses spanning the entire development lifecycle, with data from over 175,000 CVEs mapped to 643 CWEs.

Key Changes in 2025

The 2025 edition introduces significant updates:

Two New Categories: Software Supply Chain Failures and Mishandling of Exceptional Conditions
One Consolidation: Server-Side Request Forgery (SSRF) merged into Broken Access Control
Root Cause Focus: Emphasis on identifying underlying causes rather than symptoms
Expanded Data: Analysis covers 2.8 million applications with 248 CWEs across 10 categories

The OWASP Top 10: 2025

A01:2025 – Broken Access Control

Status: Remains #1 (unchanged from 2021, now includes SSRF)

Broken Access Control maintains its position at #1 as the most serious application security risk, with data indicating that on average, 3.73% of applications tested had one or more of the 40 Common Weakness Enumerations in this category.

What It Is: Access control enforces policies ensuring users cannot act outside their intended permissions. Failures lead to unauthorized information disclosure, data modification or destruction, or performing business functions beyond user limits.

Attack Methods:

Horizontal privilege escalation (accessing another user’s data by modifying URL parameters)
Vertical privilege escalation (gaining administrative privileges)
Insecure direct object references
CORS misconfigurations
Token manipulation
Server-Side Request Forgery (newly added to this category)

Potential Impact:

Unauthorized data access and exfiltration
Data modification or destruction
Complete system compromise
Unauthorized functionality access

Prevention:

Implement deny-by-default policies
Enforce server-side access controls
Use proper authentication and session management
Log access control failures and alert administrators

A02:2025 – Security Misconfiguration

Status: Moved UP from #5 to #2

Security Misconfiguration rose from #5 to #2, with every tested application showing some form of misconfiguration, and over 719,000 mapped CWEs.

What It Is: Systems, applications, or cloud services set up incorrectly from a security perspective, creating vulnerabilities through weak configurations or insecure defaults.

Common Issues:

Exposed default accounts and passwords
Unnecessary services and features enabled
Insecure file and directory permissions
Missing security headers
Verbose error messages revealing system details
Outdated or unpatched systems
Misconfigured cloud storage and services

Potential Impact:

Unauthorized system access
Data compromise and exposure
Complete system takeover

Prevention:

Use secure configuration templates
Implement minimal platform configurations
Automate configuration management
Regular security audits and scanning
Disable unnecessary features and services

A03:2025 – Software Supply Chain Failures

Status: NEW (expansion of A06:2021 – Vulnerable and Outdated Components)

Software supply chain failures are breakdowns or other compromises in the process of building, distributing, or updating software, often caused by vulnerabilities or malicious changes in third-party code, tools, or other dependencies.

What It Is: Compromises occurring within or across the entire ecosystem of software dependencies, build systems, and distribution infrastructure. This includes both known and unknown vulnerabilities introduced by third parties.

Attack Vectors:

Malicious packages and compromised dependencies
Compromised package maintainers
Tampered build processes
Vulnerabilities in CI/CD pipelines
Insecure software update mechanisms
Lack of dependency verification

Potential Impact:

Widespread system compromise
Data theft and destruction
Supply chain propagation of attacks
Loss of software integrity

Prevention:

Implement Software Bill of Materials (SBOM)
Use dependency scanning and verification tools
Monitor for compromised packages
Secure build and CI/CD pipelines
Verify package signatures and checksums
Maintain updated dependency inventories

A04:2025 – Cryptographic Failures

Status: Dropped from #2 to #4

What It Is: Failures related to lack of cryptography, insufficiently strong cryptography, leaking of cryptographic keys, and related errors. This focuses on root causes rather than the symptom of sensitive data exposure.

Common Failures:

Transmission of data in clear text
Use of weak or deprecated cryptographic algorithms
Improper key management
Missing or weak encryption at rest
Insufficient randomness in cryptographic functions
Improper certificate validation

Potential Impact:

Sensitive data privacy compromise
Data integrity compromise
Man-in-the-middle attacks
Credential theft

Prevention:

Encrypt all sensitive data in transit and at rest
Use strong, modern cryptographic algorithms
Implement proper key management
Disable deprecated protocols and ciphers
Use HTTPS with proper certificate validation

A05:2025 – Injection

Status: Dropped from #3 to #5

What It Is: System flaws allowing attackers to insert malicious code or commands into program input fields, tricking the system into executing them as if they were legitimate system commands.

Injection Types:

SQL injection
Command injection
LDAP injection
XPath injection
NoSQL injection
OS command injection
Expression language injection

Attack Method: Attackers send untrusted, malicious text-based data through various entry points including OS commands, SMTP headers, XML parsers, and database queries.

Potential Impact:

Complete data loss or corruption
Data theft and exfiltration
Access denial and system crashes
Host takeover
Remote code execution

Prevention:

Use parameterized queries and prepared statements
Implement input validation with allowlists
Apply context-appropriate output encoding
Use ORM frameworks properly
Employ least privilege for database accounts
Regular application scanning with SAST/DAST tools

A06:2025 – Insecure Design

Status: Dropped from #4 to #6

What It Is: Architectural or logical flaws rather than implementation mistakes. These are missing or ineffective control designs that exist before any code is written.

Common Issues:

Lack of threat modeling
Weak authentication flows
Missing authorization steps
Insufficient business logic validation
Absence of security requirements
Poor architectural decisions

Potential Impact:

Fundamental security weaknesses
Business logic bypass
Data exposure through design flaws

Prevention:

Implement threat modeling early in design
Use secure design patterns and principles
Perform design-stage security reviews
Establish secure development lifecycle
Create and use secure component libraries

A07:2025 – Authentication Failures

Status: No change from #7 (renamed from Identification and Authentication Failures)

What It Is: Systems that fail to properly verify or protect user identities and authentication mechanisms, allowing attackers to impersonate legitimate users or gain unauthorized access.

Common Vulnerabilities:

Weak password policies
Credential stuffing vulnerabilities
Missing or improper multi-factor authentication
Session fixation attacks
Exposed session identifiers
Lack of account lockout mechanisms
Insecure password recovery processes

Potential Impact:

Account takeover
Identity theft
Unauthorized system access
Credential compromise

Prevention:

Implement multi-factor authentication
Use strong password policies
Protect against automated attacks
Secure session management
Implement account lockout mechanisms
Log authentication failures

A08:2025 – Software and Data Integrity Failures

Status: No change from #8

What It Is: Code and infrastructure that fails to protect against invalid or untrusted code or data being treated as trusted and valid, focusing on lower-level trust boundaries.

Common Issues:

Insecure deserialization
CI/CD pipeline compromises
Auto-updates without integrity verification
Untrusted software sources
Lack of digital signature verification
Missing integrity checks

Potential Impact:

Remote code execution
System compromise
Data tampering
Malware installation

Prevention:

Use digital signatures for software updates
Verify integrity of critical data and code
Implement CI/CD pipeline security
Use trusted repositories only
Employ runtime application self-protection

A09:2025 – Security Logging and Alerting Failures

Status: No change from #9 (renamed to emphasize alerting)

This category has a slight name change to emphasize the importance of the alerting functionality needed to induce appropriate action on relevant logging events.

What It Is: Gaps in monitoring, logging, or alerting that allow attacks to go undetected. Great logging without alerting provides minimal value in identifying security incidents.

Common Failures:

Insufficient or inconsistent logging
Unmonitored logs
Tamperable or deletable logs
Missing alerts for suspicious activity
Excessive false positives overwhelming security teams
Logs not integrated with SIEM systems

Potential Impact:

Delayed incident detection
Inability to perform forensics
Prolonged breaches
Compliance violations

Prevention:

Log all security-relevant events
Implement centralized log management
Set up real-time alerting
Protect log integrity
Regular log review and analysis
Integrate with SIEM/SOC processes

A10:2025 – Mishandling of Exceptional Conditions

Status: NEW category for 2025

This new addition addresses poor error and exception handling that leads to unpredictable or insecure behavior, with 24 CWEs including leaking sensitive errors and failing securely.

What It Is: Programs that fail to prevent, detect, and respond to unusual and unpredictable situations, leading to crashes, unexpected behavior, and vulnerabilities.

Common Issues:

Improper input validation
Incomplete error recovery
“Failing open” instead of “failing closed”
Inconsistent exception handling
Verbose error messages exposing sensitive data
NULL pointer dereferences
Resource exhaustion handling

Potential Impact:

System crashes and denial-of-service
Logic flaws and security bypass
Data corruption
Sensitive information leakage through error messages

Prevention:

Define secure failure modes (fail closed, deny access on error)
Use consistent error-handling frameworks
Log details internally, return generic messages externally
Validate all inputs thoroughly
Test for edge cases and abnormal conditions
Implement proper exception handling throughout code

Root Causes of Modern Vulnerabilities

A shift from symptoms to root causes defines the 2025 update, with OWASP explicitly stating that it aims to focus more on root causes rather than symptoms.

The persistence and evolution of these vulnerabilities stem from several factors:

Attack Vector Evolution: Attackers continuously develop new techniques and exploit methods
Automated Software Development: Rapid development processes may overlook security considerations
Third-party Dependencies: Proliferation of external frameworks and libraries increases attack surface
Rapid Technology Adoption: Quick adoption of new technologies like APIs, cloud services, and containers without adequate security measures
Complex Software Ecosystems: Modern applications rely on numerous interconnected components and services
Configuration Complexity: Increased configurability creates more opportunities for misconfiguration

How Organizations Should Respond

Based on the 2025 OWASP findings, organizations should:

Establish Repeatable Security Processes: Implement standard security controls across all environments
Secure the Software Supply Chain: Monitor dependencies, verify package integrity, and maintain SBOMs
Implement Secure Design Principles: Integrate security from the design phase through deployment
Enhance Visibility: Deploy comprehensive logging, monitoring, and alerting systems
Plan for Failure: Design systems that fail safely and predictably
Continuous Security: Build a culture of ongoing security assessment and improvement
Use Security Frameworks: Adopt maturity models like SAMM, DSOMM, and ASVS for comprehensive security

Evolution from Previous Versions

Comparison: Historical OWASP Top 10 to 2025

Removed as Separate Categories:

Cross-Site Scripting (now part of Injection)
Sensitive Data Exposure (replaced by Cryptographic Failures – root cause focus)
Server-Side Request Forgery (consolidated into Broken Access Control)
Vulnerable and Outdated Components (expanded to Software Supply Chain Failures)

New Additions:

Software Supply Chain Failures (2025)
Mishandling of Exceptional Conditions (2025)
Insecure Design (added in 2021, maintained in 2025)

Renamed Categories:

Identification and Authentication Failures → Authentication Failures
Security Logging and Monitoring Failures → Security Logging and Alerting Failures

Looking Ahead

The OWASP Top 10: 2025 reflects the maturation of application security as a discipline. The focus has shifted from isolated vulnerabilities to systemic risks spanning the entire software development lifecycle. As noted in the release candidate, the final version is expected in early 2026 after community feedback is incorporated.

Organizations should view the OWASP Top 10 not as a complete security framework but as an awareness baseline that helps prioritize the most impactful security investments. For comprehensive security programs, OWASP recommends combining the Top 10 with other resources like the OWASP API Security Top 10, OWASP Top 10 for LLM Applications, and maturity assessment frameworks.

Next Steps for Security Teams

Review Current Posture: Assess your applications against the 2025 Top 10
Prioritize Remediation: Focus on categories with the highest risk to your organization
Update Security Practices: Incorporate supply chain security and resilience testing
Train Development Teams: Ensure developers understand these risks and countermeasures
Implement Continuous Testing: Integrate security testing throughout the SDLC
Monitor and Respond: Establish robust logging, alerting, and incident response capabilities

The OWASP Top 10: 2025 provides a roadmap for building more secure applications in an increasingly complex threat landscape. By understanding these vulnerabilities and implementing appropriate countermeasures, organizations can significantly reduce their security risk and protect their users’ data and trust.