CVE-2025-13466: Vulnerability In Body-parser-1.19.0

This article delves into the CVE-2025-13466 vulnerability, a medium-severity security flaw detected in body-parser-1.19.0.tgz. We will explore the technical details of this vulnerability, its potential impact, and the recommended steps to mitigate the risk. This analysis is crucial for developers and system administrators using the body-parser library, especially within Node.js applications, to understand the implications and take necessary actions to secure their systems. The discussion category for this issue includes rons1 and amazon-cloud, indicating projects or environments potentially affected by this vulnerability. Understanding the specifics of CVE-2025-13466 is essential for maintaining the security and stability of applications that rely on the body-parser middleware.

Understanding the Vulnerable Library: body-parser 1.19.0

The body-parser library is a crucial piece of middleware for Node.js applications, primarily used for parsing incoming request bodies. Specifically, it handles the processing of data sent in various formats, such as JSON, URL-encoded, and raw text. The version in question, body-parser-1.19.0.tgz, is susceptible to CVE-2025-13466, a vulnerability that can lead to denial of service (DoS) attacks. To elaborate, body-parser simplifies the process of extracting information from HTTP request bodies, making it easier for developers to access and use the data transmitted by clients. This functionality is vital for web applications that receive data from forms, APIs, or other sources. However, vulnerabilities like CVE-2025-13466 highlight the importance of staying updated with the latest security patches and understanding the potential risks associated with using outdated versions of libraries. The library's home page, as indicated in the provided information, is located at https://registry.npmjs.org/body-parser/-/body-parser-1.19.0.tgz, which serves as a central repository for Node.js packages.

The vulnerability was identified within a dependency hierarchy that includes express-4.17.1.tgz as the root library, which in turn relies on the vulnerable body-parser-1.19.0.tgz component. This dependency chain illustrates how vulnerabilities can propagate through software ecosystems, emphasizing the need for comprehensive dependency management and security scanning practices. The vulnerable library is located at /node_modules/body-parser/package.json within a project's file structure, a typical location for Node.js dependencies installed via npm or yarn. The presence of this vulnerability was found in the HEAD commit 643cdc2c42da5d86a9f12ac491138deab4a7b222 of the rons1/amazon-cloud repository on GitHub, specifically within the master branch. This information is crucial for developers and security teams as it pinpoints the exact location and context of the vulnerability, enabling targeted remediation efforts. Addressing this vulnerability involves updating the body-parser library to a patched version, which we will discuss in more detail later in this article.

Detailed Look at the Vulnerability: Denial of Service

The core issue behind CVE-2025-13466 is a denial-of-service (DoS) vulnerability stemming from the inefficient handling of URL-encoded bodies containing a large number of parameters. This flaw in body-parser 2.2.0 allows an attacker to exploit the system by sending payloads with thousands of parameters within the default 100KB request size limit. The inefficient processing of these requests leads to elevated CPU and memory usage on the server, potentially causing service slowdowns or even partial outages. The attack takes advantage of the library's inability to handle a high volume of parameters efficiently, causing it to consume excessive resources. This type of vulnerability is particularly concerning because it does not require the attacker to have any special privileges or access to the system. Instead, they can simply send malicious requests to overwhelm the server.

To further clarify, a DoS attack aims to make a system or service unavailable to its intended users by flooding it with traffic or requests. In the context of CVE-2025-13466, the vulnerability allows attackers to trigger a DoS condition by exploiting the way body-parser handles URL-encoded data. URL-encoded data is commonly used in web forms and other types of HTTP requests to transmit data between the client and the server. When a request contains a large number of parameters, the body-parser library in version 2.2.0 can struggle to process this data efficiently, leading to resource exhaustion. This can manifest as slow response times, application crashes, or even complete service unavailability. The severity of this vulnerability is compounded by the fact that it can be triggered within the default request size limits, meaning attackers can launch an attack without needing to send exceptionally large payloads. Understanding the technical details of this vulnerability is crucial for implementing effective mitigation strategies and ensuring the continued availability of web applications.

CVSS 3 Score Analysis: Severity and Impact

The CVSS (Common Vulnerability Scoring System) v3 score for CVE-2025-13466 is 5.8, indicating a medium severity level. This score provides a standardized way to assess the severity of security vulnerabilities. The CVSS score is broken down into several metrics, which help to provide a comprehensive understanding of the vulnerability's potential impact. The base score of 5.8 reflects the inherent characteristics of the vulnerability, such as its exploitability and impact, independent of any environmental or temporal factors. Let's delve into the specific metrics that contribute to this score.

Exploitability Metrics:

The exploitability metrics focus on the ease with which the vulnerability can be exploited. For CVE-2025-13466, the following exploitability metrics are relevant:

• Attack Vector: Network (N). This means the vulnerability can be exploited over a network, allowing attackers to launch an attack remotely. The attack does not require physical access to the system, making it more accessible to potential adversaries.
• Attack Complexity: Low (L). The attack is relatively easy to execute, requiring minimal technical expertise or specific conditions. This increases the likelihood of the vulnerability being exploited.
• Privileges Required: None (N). No authentication or privileges are required to exploit the vulnerability. This means that anyone can potentially launch an attack, further increasing the risk.
• User Interaction: None (N). The attack does not require any interaction from the user, such as clicking on a link or opening a file. This makes the attack more stealthy and easier to carry out.
• Scope: Changed (C). An exploitation of this vulnerability can affect resources beyond the attacker's control, potentially impacting other components or systems. This highlights the broader impact that the vulnerability can have on an organization's infrastructure.

Impact Metrics:

The impact metrics assess the potential consequences of a successful exploit. For CVE-2025-13466, the following impact metrics are relevant:

• Confidentiality Impact: None (N). The vulnerability does not lead to the disclosure of sensitive information or data. This means that the confidentiality of the system is not compromised.
• Integrity Impact: None (N). The vulnerability does not allow an attacker to modify or corrupt data. This means that the integrity of the system is not compromised.
• Availability Impact: Low (L). The vulnerability can cause a partial disruption of service, leading to slowdowns or temporary unavailability. This is the primary concern for CVE-2025-13466, as it can lead to denial of service.

For a more detailed understanding of CVSS3 scores, you can refer to the CVSS v3.0 Calculator provided by FIRST (Forum of Incident Response and Security Teams). This calculator allows you to input the various metrics and see how they contribute to the overall score. In summary, the CVSS 3 score of 5.8 for CVE-2025-13466 indicates a medium-severity vulnerability with a potential for denial of service, primarily due to its easy exploitability over a network without requiring any privileges or user interaction.

Suggested Fix: Upgrading to Version 2.2.1

The recommended solution to address CVE-2025-13466 is to upgrade the body-parser library to version 2.2.1 or later. This version includes a fix that mitigates the vulnerability related to inefficient handling of URL-encoded bodies with a large number of parameters. The fix was released on 2025-11-24, underscoring the importance of timely updates to address security vulnerabilities. Upgrading the library is a straightforward process that can significantly reduce the risk of a denial-of-service attack.

Steps to Upgrade body-parser:

1. Identify the current version: First, you need to determine the version of body-parser currently installed in your project. You can do this by checking your project's package.json file or by running the command npm list body-parser or yarn list body-parser in your project directory.
2. Update the dependency: Once you know the current version, you can update to the fixed version (2.2.1 or later) using npm or yarn. If you are using npm, run the command npm install body-parser@2.2.1. If you are using yarn, run the command yarn upgrade body-parser@2.2.1.
3. Verify the update: After the update, verify that the correct version of body-parser is installed by checking your package.json file or running the npm list body-parser or yarn list body-parser command again.
4. Test your application: It is crucial to test your application thoroughly after upgrading the library to ensure that the update has not introduced any compatibility issues or regressions. Pay close attention to the parts of your application that handle form data or URL-encoded data.
5. Commit the changes: Once you have verified that the update is successful and your application is working correctly, commit the changes to your version control system. This ensures that the updated dependency is tracked and shared with other developers working on the project.

The fix resolution for this vulnerability is available on GitHub at https://github.com/expressjs/body-parser.git, where you can review the changes made in version 2.2.1. Additionally, the updated package is available on npm under the name body-parser with the version number 2.2.1. By following these steps, you can effectively mitigate the risk posed by CVE-2025-13466 and ensure the security and stability of your Node.js applications. Regular updates and proactive vulnerability management are essential practices for maintaining a secure software environment.

Conclusion

In conclusion, CVE-2025-13466 represents a medium-severity vulnerability in the body-parser library, specifically version 1.19.0, which can lead to denial-of-service attacks. The vulnerability stems from the inefficient handling of URL-encoded bodies with a large number of parameters, making it possible for attackers to overwhelm the server with malicious requests. The CVSS 3 score of 5.8 underscores the importance of addressing this issue to maintain the availability and stability of web applications. To mitigate this risk, upgrading to body-parser version 2.2.1 or later is strongly recommended. This version includes a fix that resolves the vulnerability, preventing potential DoS attacks. Regular updates and proactive security measures are crucial for ensuring the ongoing security of Node.js applications.

For more information on security best practices and vulnerability management, visit OWASP (Open Web Application Security Project). This resource provides valuable insights and guidelines for developing and maintaining secure web applications.