If you keep up with cybersecurity news, you're likely familiar with the acronym CVE, which stands for Common Vulnerabilities and Exposures. A CVE is a reference number that provides a publicly disclosed record for a security flaw. CVE numbers help security professionals track and address security flaws across multiple systems and platforms. Today, we'll be diving into a recent vulnerability that affects a widely used video codec: CVE-2022-21917.

The HEVC Video Extensions Remote Code Execution Vulnerability (CVE-2022-21917) is a relatively recent exploit that poses a significant risk to users who frequently work with videos. High Efficiency Video Coding (HEVC), also known as H.265, is a video compression standard that provides more efficient video compression than its predecessor, H.264. Due to its widespread use, this vulnerability has serious implications for various systems, including web applications, mobile devices, and traditional desktop computers.

In this deep dive, we'll break down the details of this exploit, explore the problem on a technical level, and discuss ways you can protect your systems and users from its potentially devastating impact.

Exploit Details

The HEVC Video Extensions Remote Code Execution Vulnerability allows an attacker to execute arbitrary code on a target system by exploiting a flaw in the way the software handles a maliciously crafted video file. By leveraging this vulnerability, a threat actor might gain unauthorized access to a victim's system, which could lead to data loss, unauthorized system control, or further exploitation.

According to the CVE report, the vulnerability exists due to "insufficient validation of user-supplied input when parsing HEVC video files." Essentially, by crafting a malicious video file, an attacker can manipulate the way the software handles video data, potentially leading to a buffer overflow and remote code execution.

Code Snippet

Let's take a look at an example of how this vulnerability might be exploited. In this hypothetical situation, a threat actor might create a malicious HEVC video file that exploits the vulnerability. This malicious file could be sent to a victim via email, utilized in a phishing attack or embedded within a web page.

While we won't provide a complete code example of the exploit, we can outline the general idea. The attacker would potentially manipulate the video metadata by inserting special values for specific parameters that could trigger the flaw:

HEVCVideoFile {
  metadata {
    malicious_payload {

When an unsuspecting user opens the malicious video file with the vulnerable software, the software may not properly validate the video metadata or its parameters' values. This lack of validation could result in the execution of the attacker's arbitrarily supplied code, which might compromise the victim's system.

- CVE-2022-21917

To dig deeper into this vulnerability, you can consult additional resources including security advisories, patches, and related discussions:
- NVD - CVE-2022-21917
- Microsoft Security Update Guide

Mitigation and Protection

To protect against this vulnerability, it is essential to keep your software up to date. Following the disclosure of CVE-2022-21917, many software vendors have released patches to address the issue. As a result, it is crucial to ensure that all systems utilize the latest version of vulnerable software or, if applicable, have the necessary security updates installed.

It is also essential to educate your users about the potential risks associated with opening untrusted or suspicious video files. Encourage safe browsing habits and the use of secure mechanisms to verify the authenticity of downloaded files.


The HEVC Video Extensions Remote Code Execution Vulnerability (CVE-2022-21917) is a serious threat that highlights the importance of staying informed about emerging security threats and implementing the best practices for protecting your systems. By staying vigilant and keeping software up to date, you can reduce the chances of becoming a victim of this or any other cybersecurity vulnerability.


Published on: 01/11/2022 21:15:00 UTC
Last modified on: 04/01/2022 14:30:00 UTC