Modern web applications rarely rely entirely on code written by their own development teams. Libraries, frameworks, packages, plugins, APIs, SDKs, and other third-party components help developers build applications faster and add functionality without creating every feature from scratch.

However, these dependencies can also introduce security risks. A vulnerable, outdated, compromised, or poorly maintained component can affect the security of the application that depends on it. OWASP identifies vulnerable and compromised dependencies as important software supply chain risks and recommends maintaining visibility into dependencies throughout the software development lifecycle.

For organizations that need application security assessment and penetration testing, https://www.rashicore.com/web-application-security.php can be used to explore web application security services.

What Are Third-Party Dependencies?

Third-party dependencies are software components developed outside an organization's own application codebase. These can include:

• Open-source libraries
• Frameworks
• JavaScript packages
• Plugins
• APIs and SDKs
• Authentication components
• Database drivers
• Server-side packages
• Development tools

Applications can also contain transitive dependencies, where one dependency relies on another component. This can create a larger dependency chain that developers may not always see directly. OWASP notes that direct, transitive, runtime, and environmental dependencies can all contribute to inherited component risk.

Why Dependency Risks Matter

A third-party component can introduce risk when it contains a known vulnerability, is no longer maintained, has an insecure configuration, or becomes compromised upstream.

The risk can be particularly difficult to manage when applications contain a large number of dependencies or when teams do not maintain an accurate inventory of the components being used.

OWASP's 2025 Top 10 places Software Supply Chain Failures at A03 and includes risks such as vulnerable third-party components, unmaintained components, outdated software, and inadequate dependency tracking.

1. Maintain an Accurate Dependency Inventory

The first step toward dependency security is knowing which components are being used.

An inventory should ideally record:

• Component name
• Version
• Source
• License
• Application using the component
• Direct or transitive relationship
• Maintenance status
• Known security issues

A Software Bill of Materials (SBOM) can help provide this visibility. OWASP describes an SBOM as a record of dependencies that can include their versions, licenses, source information, and support status.

2. Monitor Dependencies for Vulnerabilities

Dependency security should continue after the initial software selection.

New vulnerabilities can be discovered after a library has already been integrated into an application. Regular monitoring helps development and security teams identify whether their installed components are affected.

Automated Software Composition Analysis (SCA) tools can assist with this process by identifying dependencies and checking them against vulnerability information. OWASP Dependency-Check, for example, analyzes third-party libraries and checks for publicly disclosed vulnerabilities.

3. Avoid Unsupported Components

A dependency that is no longer actively maintained can become increasingly difficult to secure.

Before adopting a third-party component, teams should consider:

• Is it actively maintained?
• Are security issues addressed promptly?
• Is the project well documented?
• Are security updates regularly released?
• Does the component have an established maintenance community?
• Is the current version supported?

OWASP recommends assessing factors such as component maturity, maintenance, security history, and the vendor's response to vulnerabilities before incorporating third-party components.

4. Keep Dependencies Updated

Outdated dependencies may contain vulnerabilities that have already been publicly documented and addressed in newer releases.

Regular dependency updates can reduce exposure, but updates should also be tested carefully because a new version can introduce compatibility or functional changes.

A controlled update process can include:

1. Identify outdated components.
2. Review available security fixes.
3. Check compatibility requirements.
4. Update in a development environment.
5. Run automated and security tests.
6. Deploy after validation.
7. Monitor the application after deployment.

5. Pin and Verify Dependency Versions

Uncontrolled dependency resolution can introduce unexpected changes into an application.

OWASP recommends using appropriate version pinning and validating the integrity of downloaded packages. This can help ensure that the application receives the intended component rather than an unexpected version.

Lock files and dependency-management configurations can therefore play an important role in maintaining predictable builds.

6. Protect Against Dependency Confusion

Dependency confusion is a supply chain attack technique in which an attacker attempts to cause a package manager to retrieve a malicious package instead of the intended internal or trusted package.

Organizations can reduce this risk by:

• Using trusted package sources
• Configuring package registries carefully
• Controlling package resolution
• Restricting unauthorized repositories
• Reviewing package names and sources
• Applying appropriate access controls

Development and CI/CD environments should be treated as part of the application's security boundary.

7. Review Third-Party Plugins and Integrations

Plugins and external integrations can extend application functionality, but they can also introduce additional attack surfaces.

Before installing a plugin or integration, teams should evaluate its:

• Security history
• Maintenance status
• Permissions
• Data access requirements
• Update process
• Vendor reputation
• Compatibility with the application's security requirements

OWASP recommends treating third-party plugins and integrations as software acquisitions that should be vetted, governed, updated, and removed when they are no longer required.

8. Apply Least Privilege

Third-party components should receive only the permissions they actually require.

Excessive privileges can increase the impact of a compromised component. Access should therefore be restricted wherever practical.

For example, an application plugin that only needs access to a limited dataset should not automatically receive broad access to unrelated systems or sensitive resources.

9. Include Dependencies in Web Application Security Testing

Dependency management and web application security testing should work together.

A vulnerability scanner or SCA tool may identify a known vulnerable component, while a VAPT assessment can help determine whether the application's implementation and configuration introduce additional security exposure.

Application security testing can include:

• Vulnerability assessment
• Dependency analysis
• Configuration review
• Authentication testing
• Authorization testing
• Input validation testing
• API security testing
• Manual penetration testing

For organizations looking to assess web applications from a broader security perspective, https://www.rashicore.com/web-application-security.php provides information about web application security services.

10. Use Security Testing During the Development Lifecycle

Dependency security should not be postponed until the application reaches production.

Security checks can be integrated into development and CI/CD workflows. Automated dependency analysis can identify vulnerable components during development, while additional application security testing can be performed before release.

OWASP recommends automating dependency tracking and security testing where practical as part of the software development lifecycle.

How to Build a Safer Dependency Management Process

A practical dependency management process can include:

Inventory → Assess → Monitor → Update → Test → Deploy → Reassess

First, organizations should identify all dependencies. They can then assess their security and maintenance status, monitor for new vulnerabilities, apply appropriate updates, test changes, and continuously reassess the deployed application.

This creates a repeatable process rather than relying on occasional manual checks.

Conclusion

Third-party components provide significant development benefits, but they also create security responsibilities. Vulnerable libraries, outdated packages, compromised components, and unmanaged transitive dependencies can increase the security risks of modern web applications.

Organizations can reduce these risks by maintaining an accurate dependency inventory, monitoring vulnerabilities, assessing component maintenance, controlling package sources, applying least privilege, testing updates, and continuously reviewing deployed software.

Dependency security should be treated as an ongoing part of the software development and web application security lifecycle rather than a one-time activity. Businesses looking for professional web application security assessment can explore https://www.rashicore.com/web-application-security.php.