Security researchers have recently discovered an SSRF (Server Side Request Forgery) vulnerability in the ip package used in Node.js applications before version 1.1.9. This vulnerability has been assigned the CVE identifier CVE-2023-42282 and is considered to be quite critical, as it might allow an attacker to make unauthorized requests to internal resources. In this article, we will discuss the details of this vulnerability, how it can be exploited, and the best practices for mitigating this issue.

Vulnerability Details

The ip package for Node.js is commonly used for IP address manipulations. It provides utility functions that help developers with tasks like checking if an IP address is private or public, converting IP addresses to different formats, and more.

However, in versions of the package before 1.1.9, certain IP addresses (such as x7f.1) are improperly categorized as globally routable, making them vulnerable to SSRF attacks. This occurs due to a bug in the isPublic function, which is responsible for determining if an IP address is publicly accessible.

Exploit Details

The exploitation of this vulnerability would essentially consist of tricking an affected application into making an unauthorized request to an internal service or resource on behalf of the attacker. This can be achieved by providing the malicious IP address in a format that the vulnerable isPublic function would incorrectly categorize as public.

Here's a code snippet that shows the vulnerability in action

const ip = require('ip');

// This IP address should not be considered public, but it is treated as such.
const maliciousIP = 'x7f.1';

if (ip.isPublic(maliciousIP)) {
  console.log('The IP address is incorrectly identified as public:', maliciousIP);
} else {
  console.log('The IP address is correctly identified as private:', maliciousIP);
}

In the example above, the isPublic function should correctly identify the given maliciousIP as a private IP address, but due to the vulnerability, it returns true, incorrectly identifying it as a public IP address.

Original References

1. NVD - CVE-2023-42282
2. GitHub ip Package Repository
3. Release 1.1.9 Commit

Mitigation

To fix this vulnerability, developers should update their ip package to version 1.1.9 or later. This will ensure that the affected isPublic function correctly identifies IP addresses and you won’t be exposed to SSRF attacks.

To upgrade the ip package, you can use one of the following commands, depending on your package manager:

npm update ip

OR

yarn upgrade ip

Additionally, always sanitize any user-supplied data that might end up being used as an IP address in your application. This can help you further reduce the risk of SSRF attacks.

Conclusion

It is crucial to maintain up-to-date dependencies in your software projects to avoid falling victim to security vulnerabilities like the one highlighted in this article. Always keep an eye on the latest security updates and best practices to ensure that your applications stay secure and reliable.

Timeline

Published on: 02/08/2024 17:15:10 UTC
Last modified on: 03/06/2024 15:26:20 UTC