CVE-2022-43249: Understanding the Heap-Buffer-Overflow Vulnerability in Libde265 v1..8 and How to Mitigate the Risk

The CVE-2022-43249 vulnerability was recently discovered in Libde265. This library is a popular open-source implementation of the High-Efficiency Video Coding (HEVC/H.265) video compression standard. It is widely used in many applications for decoding, encoding, and streaming HEVC video content.

This post will dive deep into the details of the CVE-2022-43249 vulnerability, including its cause, possible exploitation, and some suggestions for mitigating the risk associated with this security issue. We'll start by examining the code snippet where the vulnerability exists and then explore the original references and exploit details.

Heap-Buffer-Overflow Vulnerability

The CVE-2022-43249 vulnerability is characterized as a heap-buffer-overflow, which occurs when a program writes more data to a buffer than it can hold. This can lead to memory corruption, which may result in a crash or allow an attacker to execute arbitrary code on a target system.

In this case, the vulnerability is found in the put_epel_hv_fallback<unsigned short> function within the fallback-motion.cc file. Here's the relevant code snippet:

template<typename pixel_t>
void put_epel_hv_fallback(mxu::array2d<pixel_t>& dst, const mxu::array2d<pixel_t>& src, int mx, int my, int weight) {
// ...
}

The problem arises when this function is fed with input it can't handle, leading to a potential heap-buffer-overflow situation. Attackers can exploit this vulnerability using a specially crafted video file, which will trigger the buffer overflow and ultimately cause a denial-of-service (DoS) condition.

Original References and Exploit Details

The discovery of this vulnerability was first reported by National Vulnerability Database (NVD) and is assigned with the identifier CVE-2022-43249. Further investigation and analysis were conducted by security researchers, who published their findings, as well as proof-of-concept (PoC) exploit code, on GitHub.

The aforementioned exploit involves creating a malicious video file and using it to trigger the heap-buffer-overflow vulnerability in the Libde265 library. Once triggered, the exploitation can lead to a denial-of-service (DoS) condition. However, no evidence currently suggests that the vulnerability can be used for remote code execution.

To mitigate the risks associated with CVE-2022-43249, you should take the following steps

1. Update your Libde265 library to the latest version. As of the time of writing, the current version is v1..8. The developers behind the library are expected to release a patch to fix this issue in future updates. Keep an eye on the official repository for any new releases and update your library accordingly.

2. For application developers, ensure proper input validation and error handling in your code when working with video files. This will help prevent potential exploitation scenarios such as crafted video files that may trigger the vulnerability.

3. Educate users who interact with video files on the importance of safe downloading and sharing practices, as well as the potential risks of opening unknown or suspicious files.

Conclusion

The CVE-2022-43249 vulnerability brings to light the ever-present security challenges faced by modern software libraries. It is essential to keep your software up-to-date and follow best practices when dealing with sensitive input data such as video files. By staying informed and taking appropriate measures, you can minimize the risks posed by CVE-2022-43249 and protect your applications and data from potential attacks.

Timeline

Published on: 11/02/2022 14:15:00 UTC
Last modified on: 02/27/2023 15:25:00 UTC