CVE-2024-5492: Open Redirect Vulnerability in NetScaler ADC and NetScaler Gateway - Exploitation, Mitigation, and Remediation

CVE-2024-5492 is a security vulnerability that affects NetScaler ADC and Gateway devices. This open redirect vulnerability allows a remote unauthenticated attacker to redirect users to arbitrary websites. NetScaler Application Delivery Controller (ADC) and NetScaler Gateway are both widely used for load balancing, web app security, and enabling remote access to internal resources via VPNs. Therefore, exploiting this vulnerability in these devices could have significant impacts on affected organizations.

This long-read article will discuss the details of CVE-2024-5492, how it can be exploited, how organizations can mitigate and remediate the vulnerability, and links to original references for further information.

Exploit Details

An open redirect vulnerability occurs when a web application can be tricked into redirecting its users to an arbitrary website of an attacker's choosing. This is often accomplished by modifying the URLs sent to the web application, injecting a malicious URL into the application's redirect process, or taking advantage of unvalidated HTTP response headers.

For CVE-2024-5492, the specific issue arises in the NetScaler ADC and NetScaler Gateway's handling of redirect URLs, allowing attackers to manipulate the URL to redirect the user to a malicious website rather than the intended destination. This can lead to phishing attacks, theft of confidential data, or drive-by downloads of malware.

An example of a malicious URL exploiting this open redirect vulnerability can be seen in the code snippet below:

https://vulnerable_netscaler.example.com/cgi/login?redirect_url=https://attacker.example.com/malicious_page

When a user visits the above URL, they will be redirected to the attacker's malicious_page instead of the intended destination within the vulnerable_netscaler.example.com domain.

Mitigation

One method to mitigate this vulnerability is by implementing appropriate input validation and URL handling on the NetScaler ADC and NetScaler Gateway devices. This can involve:

Requiring user interaction before redirecting.

By using these measures, organizations can prevent attackers from exploiting the open redirect vulnerability in their NetScaler ADC or Gateway deployments.

Remediation

Citrix, the company responsible for NetScaler ADC and Gateway, has released patches and security updates addressing this vulnerability. The following resources provide detailed information about the security updates, affected versions, and remediation steps:

1. Citrix Security Bulletin CTX267027 - This security bulletin provides information about the vulnerability, affected products, and the security updates available to remediate the issue.
2. Citrix Security Advisory CVE-2024-5492 - This security advisory includes additional details about the vulnerability, including the CVSS score, attack vectors, and links to related resources.

Organizations should apply these patches and updates to their NetScaler ADC and Gateway deployments to remediate the CVE-2024-5492 open redirect vulnerability.

Conclusion

CVE-2024-5492 is a significant open redirect vulnerability affecting NetScaler ADC and NetScaler Gateway devices. By exploiting this vulnerability, attackers can redirect users to arbitrary websites, potentially leading to phishing attacks, data theft, or malware infections. Organizations should act to mitigate and remediate this issue to secure their NetScaler deployments, following the guidance provided in this article and the original references linked.

Timeline

Published on: 07/10/2024 19:15:11 UTC
Last modified on: 08/01/2024 13:59:48 UTC