CVE-2025-13466: Body-parser 1.19.0 Vulnerability

by Alex Johnson 49 views

This article discusses the medium severity vulnerability, CVE-2025-13466, detected in version 1.19.0 of the body-parser Node.js middleware library. This vulnerability can lead to a denial-of-service (DoS) attack. We will delve into the details of the vulnerability, its potential impact, and the suggested fix.

Vulnerability Details

Vulnerable Library: body-parser-1.19.0.tgz

The vulnerability exists in the body-parser library, specifically version 1.19.0. body-parser is a crucial piece of middleware for Node.js applications, responsible for parsing incoming request bodies before they are handled by your routes. It handles various content types, such as JSON, URL-encoded data, and more.

Dependency Hierarchy

The vulnerability is present in the dependency hierarchy as follows:

  • express-4.17.1.tgz (Root Library)
    • :x: body-parser-1.19.0.tgz (Vulnerable Library)

This indicates that the body-parser vulnerability is introduced as a dependency of the express framework, a widely used Node.js web application framework. If your project uses express and includes body-parser version 1.19.0, it is susceptible to this vulnerability. Identifying the dependency chain is a critical step in assessing the impact of the vulnerability on your application.

Affected Commit

The vulnerability was found in the HEAD commit: 2cbae7a110c1f8cf54415e50a3d3732a81b4c1c5

The vulnerability is also present in the base branch: master

Vulnerability Explanation

The core of the CVE-2025-13466 vulnerability lies in the inefficient handling of URL-encoded bodies when they contain a large number of parameters. Specifically, body-parser versions prior to 2.2.1 are susceptible to a denial-of-service (DoS) attack. An attacker can exploit this by sending a specially crafted payload containing thousands of parameters within the default 100KB request size limit.

This flood of parameters consumes excessive CPU and memory resources on the server. The inefficient parsing and processing of these numerous parameters can lead to a significant slowdown in service or even a partial outage. This impact is particularly pronounced under sustained malicious traffic, making the application unresponsive to legitimate user requests.

The root cause is how the body-parser library handles URL-encoded data. When a large number of parameters are submitted, the parsing process becomes computationally expensive. This expense, combined with the resource limitations of the server, creates a perfect storm for a DoS attack. The server becomes overwhelmed trying to process the malicious request, leaving fewer resources available for legitimate users.

This vulnerability underscores the importance of input validation and resource management in web applications. While body-parser simplifies the process of handling request bodies, it also introduces potential security risks if not properly managed. Developers must be aware of these risks and take appropriate measures to mitigate them.

Impact of the Vulnerability

The impact of CVE-2025-13466 is significant, particularly for applications that rely heavily on body-parser for handling user input. The vulnerability allows an attacker to trigger a denial-of-service (DoS) condition, which can severely disrupt the availability of the application.

Denial of Service (DoS)

The primary impact is the potential for a DoS attack. By sending a malicious payload with a large number of parameters, an attacker can exhaust the server's resources, making it unresponsive to legitimate requests. This can lead to:

  • Service Slowdown: The application may become sluggish and slow to respond, leading to a poor user experience.
  • Partial Outages: Certain functionalities or sections of the application may become unavailable.
  • Complete Outages: In severe cases, the entire application may crash, leading to a complete service outage.

Resource Exhaustion

The attack exploits the inefficient handling of a large number of parameters, leading to excessive CPU and memory usage. This resource exhaustion can impact other applications running on the same server, further exacerbating the problem.

Business Impact

The consequences of a DoS attack can extend beyond technical disruptions. Businesses may experience:

  • Loss of Revenue: If the application is unavailable, users cannot access services or make purchases, leading to financial losses.
  • Reputational Damage: Service outages can damage the reputation of the business and erode customer trust.
  • Operational Costs: Resolving the issue and mitigating the attack can incur significant operational costs.

Real-World Scenarios

Consider an e-commerce platform that relies on body-parser to handle form submissions. An attacker could send a malicious request with thousands of parameters, overwhelming the server and preventing legitimate customers from placing orders. This can lead to a direct loss of sales and damage to the platform's reputation.

Another scenario involves a web application that uses body-parser for API endpoints. An attacker could flood the API with malicious requests, causing the server to become unresponsive and disrupting the service for all users.

Importance of Prompt Remediation

Given the potential impact of this vulnerability, it is crucial to address it promptly. Upgrading to a patched version of body-parser is the recommended solution, as it mitigates the risk of DoS attacks and ensures the continued availability of the application.

CVSS 3 Score Details (5.8)

The Common Vulnerability Scoring System (CVSS) provides a standardized way to assess the severity of vulnerabilities. The CVSS 3 score for CVE-2025-13466 is 5.8, indicating a Medium severity vulnerability.

Base Score Metrics

The base score is calculated based on several metrics that reflect the intrinsic characteristics of the vulnerability. These metrics are divided into Exploitability Metrics and Impact Metrics.

Exploitability Metrics

  • Attack Vector: Network (AV:N): This indicates that the vulnerability can be exploited over a network, meaning an attacker can trigger the vulnerability remotely.
  • Attack Complexity: Low (AC:L): The vulnerability is easy to exploit, requiring little or no specialized knowledge or resources.
  • Privileges Required: None (PR:N): An attacker does not need any privileges or credentials to exploit the vulnerability.
  • User Interaction: None (UI:N): No user interaction is required to trigger the vulnerability. The attacker can exploit it without any involvement from the user.
  • Scope: Changed (S:C): An exploited vulnerability can affect resources beyond the security scope managed by the security authority of the vulnerable component.

Impact Metrics

  • Confidentiality Impact: None (C:N): The vulnerability does not allow an attacker to gain access to sensitive information.
  • Integrity Impact: None (I:N): The vulnerability does not allow an attacker to modify data or system resources.
  • Availability Impact: Low (A:L): The vulnerability can cause a partial loss of service availability.

Interpretation of the Score

The CVSS 3 score of 5.8 indicates that the vulnerability is moderately severe. While it does not directly impact confidentiality or integrity, the potential for a denial-of-service (DoS) attack poses a significant threat to the availability of the application.

The high exploitability metrics (Network attack vector, Low complexity, No privileges required, No user interaction) indicate that the vulnerability is easy to exploit, making it attractive to attackers. The changed scope further emphasizes the potential impact, as the vulnerability can affect resources beyond the vulnerable component.

Importance of Understanding CVSS Scores

Understanding CVSS scores is crucial for prioritizing vulnerability remediation efforts. Vulnerabilities with higher CVSS scores should be addressed more urgently, as they pose a greater risk to the application and the organization. In this case, while the score is medium, the ease of exploitation and the potential for DoS make it a priority to address.

For more information on CVSS3 Scores, click here.

Suggested Fix

To mitigate the CVE-2025-13466 vulnerability in body-parser, the suggested fix is to upgrade to version 2.2.1 or later. This version includes a patch that addresses the inefficient handling of URL-encoded bodies with a large number of parameters, thus preventing the denial-of-service (DoS) attack.

Type: Upgrade Version

The recommended solution is to upgrade the body-parser library to a version that includes the fix for the vulnerability. This is a straightforward and effective way to address the issue.

Release Date: 2025-11-24

The patched version 2.2.1 was released on 2025-11-24. Ensure that you are using a version released on or after this date to benefit from the fix.

Fix Resolution

The fix is available in the following repositories and versions:

How to Upgrade

To upgrade body-parser in your Node.js project, you can use npm or yarn, depending on your package manager of choice.

Using npm:

npm install body-parser@2.2.1

Using yarn:

yarn add body-parser@2.2.1

After running the upgrade command, ensure that you have updated the dependency in your package.json file. It is also recommended to test your application thoroughly after the upgrade to ensure that everything is working as expected.

Additional Recommendations

  • Regularly Update Dependencies: Keep your project dependencies up to date to benefit from security patches and bug fixes.
  • Use a Vulnerability Scanner: Incorporate a vulnerability scanner into your development workflow to identify and address vulnerabilities early on.
  • Implement Input Validation: Validate and sanitize user input to prevent malicious data from reaching your application.

Conclusion

The CVE-2025-13466 vulnerability in body-parser-1.19.0 poses a risk of denial-of-service (DoS) attacks due to inefficient handling of URL-encoded bodies with a large number of parameters. The vulnerability has a CVSS 3 score of 5.8, indicating a medium severity. To mitigate this risk, it is strongly recommended to upgrade to body-parser version 2.2.1 or later. This upgrade addresses the vulnerability and helps ensure the continued availability and stability of your applications.

Remember to always prioritize security in your development practices, regularly update your dependencies, and leverage security tools to identify and address vulnerabilities proactively. For more in-depth information on vulnerability management and best practices, consider exploring resources from trusted cybersecurity organizations. You can find valuable information and guidance on websites like OWASP (Open Web Application Security Project).