CVE-2020-28481: Insecure Defaults due to CORS Misconfiguration in socket.io
Summary
CVE-2020-28481: CORS misconfiguration in socket.io. Affects socket.io versions < 2.4.0. Fixed in 2.4.0. How to fix ↓
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Background
Socket.io is a popular JavaScript library that enables real-time, bidirectional communication between web clients and servers. It provides a simple and reliable way to build scalable and efficient applications. However, versions before 2.4.0 are vulnerable to an Insecure Defaults issue due to CORS misconfiguration. By default, all domains are whitelisted, which can lead to potential security risks.
Vulnerability Detail
The vulnerability arises from the insecure default configuration of Cross-Origin Resource Sharing (CORS) in socket.io. CORS is a security mechanism that restricts cross-origin requests in web browsers. In socket.io versions prior to 2.4.0, all domains are whitelisted by default, allowing any website to make cross-origin requests to the socket.io server. This can lead to various security issues, such as unauthorized access to sensitive data or the execution of malicious actions on behalf of authenticated users.
How To Fix
Minimum fixed version
2.4.0
This is the first release that contains the fix.
npm install socket.io@2.4.0Tip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
If upgrading to the latest version is not feasible, a temporary workaround is to manually configure the CORS settings to restrict access to trusted domains only. This can be done by modifying the server-side code that initializes the socket.io server. Below is an example of how to configure CORS to allow requests only from 'example.com':
const io = require('socket.io')();
io.origins('https://example.com');
// Rest of the socket.io server initialization code
Conclusion
Insecure Defaults due to CORS Misconfiguration in socket.io (CVE-2020-28481) can pose significant security risks to applications using vulnerable versions of socket.io. It is crucial to upgrade to version 2.4.0 or later to mitigate this vulnerability. Administrators should also review and adjust the CORS configuration based on their specific requirements and security policies. For further support and assistance in vulnerability remediation, please contact DevNack.com.
See every vulnerability recorded for socket.io →
FAQ
Socket.io is a JavaScript library that enables real-time, bidirectional communication between web clients and servers. It simplifies the development of applications that require real-time updates and interactive features.
Cross-Origin Resource Sharing (CORS) is a security mechanism that restricts cross-origin requests in web browsers. It allows servers to specify which origins are allowed to access their resources.
The insecure default CORS configuration in socket.io can lead to unauthorized access to sensitive data, cross-site scripting (XSS) attacks, and the execution of malicious actions on behalf of authenticated users.
You can use the Vulert Playground at Vulert Scanner to check if your application is affected by this vulnerability. Vulert monitors and alerts in real-time for open-source vulnerabilities, using just the package-lock.json file.
You can refer to the official socket.io documentation and security guidelines for more information on how to secure your socket.io applications.
References
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