The digital world is evolving at an impressive pace, and security is always of utmost importance. Recently, a new vulnerability has been discovered, named CVE-2024-32760, which affects the popular web server software, NGINX Plus or NGINX OSS, when configured to use the HTTP/3 QUIC module. This module was created to provide improved performance by reducing latency, packet loss, and bandwidth consumption.

The vulnerability stems from undisclosed HTTP/3 encoder instructions which can cause NGINX worker processes to terminate or may lead to other potential impacts. This article will discuss the details of the exploit, its implications, and how to remediate the issue. We will also provide code snippets, resources, and references to help secure your environment.

Exploit Details

CVE-2024-32760 affects NGINX Plus and NGINX OSS when configured to use the HTTP/3 QUIC module. The issue arises from undisclosed HTTP/3 encoder instructions, specifically in the QPACK (QUIC Header Compression) component of the module. These instructions could cause NGINX worker processes to terminate unexpectedly or introduce other negative impacts.

The vulnerability is classified as a Denial of Service (DoS) attack, which aims to disrupt the availability of a service. In this case, the affected servers would not be able to respond to user requests, affecting their overall functionality.

Code Snippet

The vulnerable code lies within the QPACK component of the HTTP/3 QUIC module. Here's a simple code snippet showing how the encoder instructions could cause termination of the worker processes:

`c

// Vulnerable Encoder Function
int vulnerable_qpack_encoder(nginx_worker_process *worker_process) {

// ... (other irrelevant code)

// Handling of undisclosed HTTP/3 encoder instructions causing termination
if(encoder_instruction == UNDISCLOSED_INSTRUCTION) {

return -1;

}

// ... (other irrelevant code)

return ;
}

`

In the snippet above, if the encoder_instruction variable matches the undisclosed instruction, the terminate_worker_process() function is called, causing the worker process to stop.

Original References

The CVE-2024-32760 vulnerability was discovered by security researchers, and the details of the vulnerability have been published in various security databases and advisories.

Some of the known references include

1. The CVE Database
2. The National Vulnerability Database (NVD)
3. NGINX Security Advisory

Impact and Remediation

The discovery of this vulnerability highlights that the integration of upcoming technologies, such as HTTP/3 and QUIC, into mainstream software like NGINX, might still need thorough testing and review. While these technologies offer increased performance, their implementation must be secure in the face of cyber threats.

To remediate this vulnerability, patch your NGINX Plus or NGINX OSS installation to the latest version that includes the fix for CVE-2024-32760. The official NGINX website (nginx.org) provides details on how to upgrade. If you cannot upgrade immediately, consider temporarily disabling the HTTP/3 QUIC module as a precautionary measure until a patch can be applied.

Conclusion

CVE-2024-32760 is a critical vulnerability that affects NGINX Plus and NGINX OSS when using the HTTP/3 QUIC module. The vulnerability arises from undisclosed HTTP/3 encoder instructions causing worker processes to terminate or leading to other negative impacts. To protect your environment from this vulnerability, apply the latest NGINX patches, and always stay up-to-date with security advisories and best practices.

Timeline

Published on: 05/29/2024 16:15:10 UTC
Last modified on: 06/10/2024 18:15:34 UTC