A critical security vulnerability, identified as CVE-2023-4982, has been discovered in the popular open-source network monitoring tool LibreNMS. This vulnerability is related to a stored Cross-site Scripting (XSS) issue that allows malicious attackers to inject harmful code into the application. The severity of this vulnerability has been labeled as "high" and affects all users of LibreNMS prior to version 23.9..

Details

Cross-site Scripting (XSS) is a type of security vulnerability that allows an attacker to inject malicious scripts into web pages viewed by other users. In this case, the vulnerability was found in the LibreNMS GitHub repository, specifically in the file named "librenms/librenms." The vulnerability exists due to improper sanitization of user inputs.

This vulnerability allows an attacker to store malicious code or JavaScript within the application, which will then be executed when other users interact with the affected elements. In turn, this could lead to unauthorized access to sensitive data, as well as the potential for other malicious activities, such as launching further attacks or installing malware.

The following code snippet demonstrates the exploitation of this vulnerability

payload = "<script>alert('XSS vulnerability found by Malicious user');</script>";

$.ajax({
  type: "POST",
  url: "vulnerable_librenms_endpoint",
  data: {
    userInput: payload
  },
  success: function(response) {
    console.log("Vulnerability successfully exploited.");
  }
});

This code snippet makes an AJAX POST request to the vulnerable LibreNMS endpoint, injecting the malicious payload that contains an XSS attack in the userInput parameter.

Mitigation

In order to protect your organization from this vulnerability, it is essential to update your LibreNMS software to the latest version, 23.9. or later. After updating, ensure that proper input sanitization is in place to prevent any further exploitation of this vulnerability type.

To learn more about the CVE-2023-4982, visit

- CVE-2023-4982 Record on NIST NVD
- GitHub Issue Discussing and Fixing the Vulnerability
- Official LibreNMS Repository on GitHub

For additional resources on Cross-site Scripting vulnerabilities and mitigations, refer to these links:

- OWASP XSS (Cross Site Scripting) Prevention Cheat Sheet_Prevention_Cheat_Sheet)
- Mozilla Developer Network: Sanitizing user input

Conclusion

With the discovery of CVE-2023-4982, it has become increasingly important to keep your software up-to-date and to take preventive measures against stored Cross-site Scripting (XSS) attacks. By addressing this vulnerability and implementing proper coding practices, the security of your network and data can be significantly improved, ultimately protecting your organization from potential attackers.

Timeline

Published on: 09/15/2023 01:15:00 UTC
Last modified on: 09/20/2023 13:13:00 UTC