CVE-2023-3224: Code Injection Vulnerability in nuxt/nuxt prior to Version 3.5.3

A significant code injection vulnerability has been discovered in the popular GitHub repository, nuxt/nuxt, also known as "Nuxt.js"; a framework based on Vue.js that allows developers to create server-rendered applications. The vulnerability, which is tagged as CVE-2023-3224, affects versions of the platform earlier than 3.5.3. This blog post will provide an in-depth analysis of the security flaw and illustrate how attackers can exploit it in different scenarios, along with code snippets and links to the original references.

Code Injection Vulnerability Explained

The vulnerability lies in Nuxt's handling of server-side rendering (SSR), which is intended to provide better performance and user experience for front-end applications. However, an attacker can craft a malicious payload that, when processed by the SSR module, can execute arbitrary code on the back-end server, potentially causing severe damage to the target system.

To understand how the vulnerability can be exploited, let's take a look at an example code snippet

{
  app: {
    head: {
      script: [
        {
          source: console.log('${payload}'),
        },
      ],
    },
  },
}

In this example, the 'payload' is a user-supplied input parsed by the SSR engine. Suppose the 'payload' contains a malicious JavaScript code that can execute on the user's machine when rendered. In that case, the attacker can craft the payload to execute arbitrary commands on the server-side, potentially leading to unauthorized access, data theft, or even complete system compromise.

Original References and Details on the Fix

The security flaw was first reported on Nuxt.js's GitHub repository (see the issue here: https://github.com/nuxt/nuxt/issues/3224), where it was documented and acknowledged by the project maintainers. They promptly released an update (version 3.5.3), which addresses the vulnerability and effectively mitigates its impact. You can find the official release notes for this update here: https://github.com/nuxt/nuxt/releases/tag/v3.5.3.

The developers introduced a secure implementation that eliminates the possibility of the code injection. Here is the updated code snippet that properly sanitizes the 'payload':

{
  app: {
    head: {
      script: [
        {
          source: console.log('${escape(payload)}'),
        },
      ],
    },
  },
}

By employing the 'escape()' function, the updated implementation ensures that the 'payload' is correctly sanitized and no longer poses a threat to the server.

Exploit Details

To successfully exploit this vulnerability, an attacker needs to craft a malicious payload containing the desired arbitrary code, then submit it to the vulnerable Nuxt.js application. The target application, built on a version prior to 3.5.3, will process the payload using its SSR engine and execute the attacker's code on the server-side.

It is crucial to note that this vulnerability can have various degrees of severity depending on the application's architecture, server configuration, and the privileges of the attacker's code. Possible attack scenarios may include unauthorized access to restricted data, exfiltration of sensitive information, or even gaining full control over the back-end server.

Conclusion

CVE-2023-3224 is a severe code injection vulnerability in Nuxt.js that affects versions prior to 3.5.3. The issue has been patched in the latest version of the framework, and developers are strongly advised to update their applications to secure their systems against potential attacks. This in-depth analysis, including the code snippets and references, should help developers understand the risks associated with outdated versions and the potential impacts of not addressing this issue promptly.

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Timeline

Published on: 06/13/2023 18:15:00 UTC
Last modified on: 06/20/2023 17:03:00 UTC