Moment.js is a widely used JavaScript date library that makes it easy to parse, validate, manipulate, and format dates. Recently, a path traversal vulnerability was discovered in Moment.js, affecting the npm (server) users between versions 1..1 and 2.29.1, particularly when a user-provided locale string is used directly to switch Moment.js locale. This vulnerability is identified as CVE-2022-24785.

In this post, we will discuss the details of CVE-2022-24785, including the potential impact, code snippets illustrating the vulnerability, and steps to mitigate the issue. We will also provide the original references and links to patch the vulnerability.

Exploit Details

CVE-2022-24785 stems from the misuse of user-provided locale data, causing a path traversal vulnerability. An attacker can exploit this vulnerability to access sensitive files on the server, potentially exposing sensitive information and compromising the system.

Code Snippet

The following code snippet illustrates the vulnerability associated with directly using a user-provided locale string to switch the moment locale:

const Moment = require('moment');
const userInput = req.query.locale;

Moment.locale(userInput); // Security Vulnerability: Directly using user-provided locale string

In the example above, the userInput variable contains a value provided by a user and is passed directly to the Moment.locale() function without any sanitization. This unrestricted use of user input could make the system vulnerable to path traversal attacks.

Mitigation

The Moment.js team has addressed this issue in version 2.29.2. Users are strongly advised to upgrade to this version to patch the vulnerability. The patch can also be applied to all affected versions.

For those who are unable or unwilling to upgrade immediately, a workaround exists. You can sanitize the user-provided locale string before passing it to Moment.js:

const Moment = require('moment');
const userInput = req.query.locale;
const sanitizedLocale = sanitizeLocale(userInput); // Sanitize the user-provided locale

Moment.locale(sanitizedLocale);

In the code snippet above, the sanitizeLocale function should be defined to prevent any malicious input from the user. This function should check for strings that include directory traversal characters ('.' and '/') and escape them accordingly.

For more details on CVE-2022-24785, please refer to the following resources

1. Moment.js GitHub Repository
2. Moment.js Release Notes
3. CVE-2022-24785 Official Entry at CVE List

Conclusion

CVE-2022-24785 highlights the importance of proper user input sanitization and handling, especially when dealing with libraries like Moment.js. By patching the vulnerability or utilizing the provided workaround, you can help protect your applications and users from potential security risks. Stay vigilant and always prioritize keeping your dependencies up-to-date and secure.

Timeline

Published on: 04/04/2022 17:15:00 UTC
Last modified on: 07/30/2022 02:50:00 UTC