Swagger 11.2.1 Vulnerability: CVE-2025-64718

by Alex Johnson 45 views

This article dives into a critical security vulnerability discovered in swagger-11.2.1.tgz, specifically CVE-2025-64718, which has a medium severity rating of 5.3. This vulnerability affects the js-yaml library, a transitive dependency of Swagger, and could potentially expose your applications to security risks. We'll break down the vulnerability details, its impact, and how to remediate it effectively. It is important to address these vulnerabilities swiftly to maintain the integrity and security of your projects, understanding the nature and potential impact of these vulnerabilities is crucial for developers and security teams.

Understanding the Vulnerability: CVE-2025-64718

The Core Issue: Prototype Pollution in js-yaml

The vulnerability, CVE-2025-64718, lies within the js-yaml library, version 4.1.0 and below. js-yaml is a widely used JavaScript library for parsing and serializing YAML data. The vulnerability stems from a prototype pollution issue, which means an attacker could potentially modify the prototype of JavaScript objects by manipulating the parsed YAML data. This manipulation can lead to various security exploits, including:

  • Denial of Service (DoS): By polluting the prototype, an attacker could cause unexpected behavior or crashes in the application.
  • Remote Code Execution (RCE): In certain scenarios, prototype pollution can be leveraged to execute arbitrary code on the server.
  • Information Disclosure: The vulnerability could potentially be exploited to access sensitive information.

Vulnerability Details

  • Vulnerable Library: js-yaml-4.1.0.tgz
  • Severity: Medium (CVSS Score: 5.3)
  • Type: Transitive vulnerability (present in a dependency of Swagger)
  • Root Library: swagger-11.2.1.tgz
  • Path to Vulnerable Library: /package.json
  • CVSS v3 Metrics:
    • Attack Vector: Network
    • Attack Complexity: Low
    • Privileges Required: None
    • User Interaction: None
    • Scope: Unchanged
    • Confidentiality Impact: None
    • Integrity Impact: Low
    • Availability Impact: None
  • Affected Component: js-yaml 4.1.0 and below
  • Published Date: 2025-11-13

The key takeaway here is that if your application uses swagger-11.2.1.tgz and processes YAML data using js-yaml, it is potentially vulnerable. This is because the flaw allows for attackers to manipulate the properties of JavaScript objects, leading to unpredictable and potentially harmful outcomes. Prototype pollution vulnerabilities can be subtle and difficult to detect, making them a significant threat if left unaddressed. To fully understand the risk, it is vital to know where this library is being used within your project and how user-supplied data interacts with it.

Impact Analysis: How Does CVE-2025-64718 Affect Your Application?

To fully grasp the implications of CVE-2025-64718, it's essential to understand the potential impact on your application. This vulnerability, stemming from a prototype pollution issue in js-yaml, can have far-reaching consequences depending on how your application utilizes the library. Let’s delve into the specific ways this vulnerability might manifest and the potential damage it can cause.

Potential Attack Scenarios

  • Malicious YAML Input: The most direct attack vector involves an attacker providing specially crafted YAML input designed to exploit the prototype pollution vulnerability. If your application parses YAML data from untrusted sources (e.g., user uploads, external APIs), it could be vulnerable. This malicious input could inject properties into the Object.prototype, affecting the behavior of all objects in the application.
  • Cross-Site Scripting (XSS): In web applications, prototype pollution can lead to XSS vulnerabilities. By polluting the prototype, an attacker could inject malicious JavaScript code that executes in the context of a user's browser. This could allow the attacker to steal user credentials, redirect users to malicious sites, or deface the application.
  • Denial of Service (DoS): An attacker could exploit the vulnerability to cause a DoS attack by manipulating object properties in a way that leads to application crashes or resource exhaustion. For example, polluting the prototype with computationally expensive operations could slow down the application or make it unresponsive.
  • Bypassing Security Measures: Prototype pollution can sometimes be used to bypass security measures or access controls. For instance, an attacker might be able to modify object properties that control authentication or authorization, allowing them to gain unauthorized access to sensitive resources.

Real-World Implications

  • Data Breaches: If the vulnerability is used to bypass access controls or inject malicious code, it could lead to the theft of sensitive data, such as user credentials, financial information, or personal data. Data breaches can have severe consequences for your organization, including financial losses, reputational damage, and legal liabilities.
  • System Compromise: In more severe cases, the vulnerability could be exploited to gain control of the server or other systems. This could allow an attacker to install malware, steal data, or launch further attacks on your infrastructure. System compromise is a worst-case scenario that can have devastating consequences.
  • Application Instability: Even if the vulnerability is not directly exploited for malicious purposes, it can still lead to application instability and unexpected behavior. Prototype pollution can cause subtle bugs that are difficult to diagnose and fix, leading to frustration for users and developers alike.

Identifying Vulnerable Code

To determine whether your application is vulnerable, you need to identify all instances where js-yaml is used to parse YAML data. Pay particular attention to code that handles user-supplied input or data from external sources. Look for patterns such as:

  • yaml.load(untrustedInput)
  • yaml.safeLoad(untrustedInput)
  • Any other function in the js-yaml library that parses YAML data.

By carefully analyzing your code and understanding how js-yaml is used, you can assess the potential impact of CVE-2025-64718 and prioritize remediation efforts. It is essential to protect your application by minimizing the attack surface and implementing best practices for handling untrusted data. Regular security audits and penetration testing can also help identify potential vulnerabilities before they are exploited.

Remediation Strategies: Fixing CVE-2025-64718

Addressing CVE-2025-64718, the prototype pollution vulnerability in js-yaml, is critical for ensuring the security and stability of your applications. Fortunately, there are clear steps you can take to remediate this issue effectively. Let's explore the recommended strategies and how to implement them.

1. Upgrade js-yaml

The most direct and recommended solution is to upgrade js-yaml to a version that includes the fix for CVE-2025-64718. The patched versions are:

  • js-yaml version 4.1.1 or later
  • js-yaml version 3.14.2 or later

How to Upgrade

  • npm: If you are using npm, you can upgrade js-yaml by running the following command in your project directory:

    npm install js-yaml@latest

    or

    npm update js-yaml

  • Yarn: If you are using Yarn, use the following command:

    yarn upgrade js-yaml@latest

  • package-lock.json and yarn.lock: After upgrading, ensure that your package-lock.json (for npm) or yarn.lock (for Yarn) file is updated to reflect the new version. This will ensure that everyone working on the project uses the patched version.

2. Verify the Fix

After upgrading js-yaml, it's essential to verify that the vulnerability has been addressed. You can do this by:

  • Running Tests: If you have automated tests, run them to ensure that the application behaves as expected after the upgrade. Pay particular attention to tests that involve parsing YAML data.
  • Manual Testing: Manually test the application by providing various YAML inputs, including potentially malicious ones, to ensure that the prototype pollution vulnerability is no longer present.
  • Vulnerability Scanning: Use vulnerability scanning tools to check for the presence of CVE-2025-64718. These tools can automatically identify known vulnerabilities in your dependencies.

3. Mitigation Strategies (If Upgrading Is Not Immediately Possible)

In some cases, upgrading js-yaml may not be immediately feasible due to compatibility issues or other constraints. In such situations, you can implement mitigation strategies to reduce the risk of exploitation. However, these mitigations should be considered temporary measures until you can upgrade the library.

  • Input Validation: Implement strict input validation to sanitize YAML data before parsing it. This can help prevent malicious input from reaching the js-yaml parser. Use schemas to define the expected structure and data types of your YAML documents and reject any input that does not conform to the schema.
  • Sandboxing: Run the js-yaml parser in a sandboxed environment with limited privileges. This can help contain the impact of a successful exploit. For example, you can use Node.js's vm module to create a sandboxed context for parsing YAML data.
  • Prototype Freezing: You can use Object.freeze(Object.prototype) to prevent modifications to the Object.prototype. However, this approach may break compatibility with other libraries or code that relies on prototype modifications.

4. Long-Term Security Practices

In addition to addressing CVE-2025-64718, it's essential to implement long-term security practices to prevent future vulnerabilities.

  • Regular Dependency Updates: Keep your dependencies up to date with the latest versions to benefit from security patches and bug fixes. Use tools like npm's npm outdated or Yarn's yarn outdated to identify outdated dependencies.
  • Vulnerability Monitoring: Use vulnerability monitoring tools to continuously scan your dependencies for known vulnerabilities. These tools can alert you when new vulnerabilities are discovered, allowing you to take action promptly.
  • Security Audits: Conduct regular security audits of your code and infrastructure to identify potential vulnerabilities and security weaknesses.

By following these remediation strategies and adopting a proactive approach to security, you can protect your applications from CVE-2025-64718 and other vulnerabilities. Regular maintenance and a focus on security best practices are essential for building resilient and secure applications.

Conclusion

In conclusion, the CVE-2025-64718 vulnerability in js-yaml, affecting swagger-11.2.1.tgz, presents a notable security risk due to the potential for prototype pollution. This vulnerability could lead to a range of issues, from denial of service to remote code execution, highlighting the importance of prompt remediation. Understanding the intricacies of this vulnerability, including its impact and potential attack vectors, is crucial for developers and security teams.

The primary recommendation for addressing CVE-2025-64718 is to upgrade js-yaml to version 4.1.1 or later, or version 3.14.2 or later. This ensures that the patched version, which includes the fix for the prototype pollution issue, is in use. However, if immediate upgrading is not feasible, implementing mitigation strategies such as input validation, sandboxing, and prototype freezing can provide temporary relief. These strategies help to minimize the risk of exploitation until a full upgrade can be performed.

Beyond the immediate fix, adopting long-term security practices is essential for maintaining a robust security posture. This includes regular dependency updates, vulnerability monitoring, and conducting security audits. Keeping dependencies up to date ensures that you benefit from the latest security patches and bug fixes. Vulnerability monitoring tools can continuously scan your dependencies for known vulnerabilities, alerting you when new issues are discovered. Regular security audits help identify potential weaknesses in your code and infrastructure, allowing you to address them proactively.

By diligently applying these remediation strategies and adhering to security best practices, you can effectively protect your applications from CVE-2025-64718 and similar vulnerabilities. A proactive and comprehensive approach to security is vital for building resilient and secure applications, ensuring the safety and integrity of your systems and data.

For more detailed information on prototype pollution vulnerabilities and secure coding practices, consider exploring resources from trusted sources such as OWASP (Open Web Application Security Project). This proactive approach to security ensures the long-term safety and reliability of your applications.