CVE-2022-22006 - How HEVC Video Extensions Can Enable Silent Remote Code Execution on Windows

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If you’re using Windows to watch videos, you might have come across the “HEVC Video Extensions.” These extensions let Windows play high-efficiency video coding files (H.265 videos), but they also introduced a dangerous flaw logged as CVE-2022-22006. This vulnerability could allow someone to trick your computer into running their malicious code just by getting you to open a specially-made video file.

Let’s dig into what happened, see how it works, and understand how to stay safe.

What is CVE-2022-22006?

CVE-2022-22006 is a remote code execution (RCE) vulnerability in the Microsoft Windows HEVC Video Extensions. It got patched by Microsoft in June 2022 as part of their Security Update ADV220002.

This bug is not the same as CVE-2022-22007, CVE-2022-23301, CVE-2022-24452, CVE-2022-24453, or CVE-2022-24456—each affects the HEVC Extensions in a different way, but CVE-2022-22006 is unique.

Why Is This Vulnerability So Serious?

The HEVC Video Extensions are popular because they add support for playing videos encoded in H.265/HEVC, a modern and efficient codec. The extension is available via the Microsoft Store or comes pre-installed on some devices.

When a vulnerable version is present, simply opening a specially-made video file—sent via email, instant message, or downloaded from a website—could allow an attacker to run *any commands* they wish as the current user. This could include installing programs, stealing files, or taking control of the system.

How Does the Exploit Work?

Microsoft’s HEVC Video Extension processes input video files, like .mp4 or .mkv, that use the H.265 codec. The problem is that the video parsing logic had a bug where it didn’t properly check for invalid or out-of-bounds values when reading certain parts of a file.

Run commands on your PC

Here’s a very simplified example (the real exploit is more complex and would target binary structures):

char buffer[100];
memcpy(buffer, input_video_data, user_provided_length);

If user_provided_length is larger than 100, it will overwrite parts of memory it's not supposed to – potentially inserting and executing malicious code.

Attackers use fuzzers to automatically generate and test video files for these vulnerabilities, causing crashes that might indicate exploitable bugs.

Here’s how an attack might work

1. An attacker creates a malicious .mp4 video file using open-source H.265 tools and adds harmful data to trigger the bug.

They send the file to victims via email attachments, direct messages, or upload it to a website.

3. The victim opens the file on a Windows device with a vulnerable version of the HEVC Video Extensions.

How to Protect Yourself

- Update Now: Microsoft released a patched version of the HEVC Video Extensions. Go to the Microsoft Store, search for "HEVC Video Extensions," and make sure it's updated.

Windows Update: Install all the latest security updates.

- Be Cautious: Don’t open video files from strangers, especially those sent via email or instant messaging.

Enterprise Defenses

- Use EDR/XDR solutions to detect unusual video decoding activity

Microsoft Advisory

- https://msrc.microsoft.com/update-guide/vulnerability/CVE-2022-22006

Patch Notes

> “A remote code execution vulnerability exists in Microsoft Windows HEVC Video Extensions, where specially-crafted video files could trigger memory corruption. The update corrects how the codec library handles objects in memory.”

Proof-of-Concept & Exploit Code

Microsoft did not release exploit code, but security researchers have shown how malformed video files can crash the codec and redirect program execution. Fuzzing tools like AFL or Video Fuzzer can help discover such bugs.

Example Python snippet to create a corrupt video (for research only):

with open('malicious.mp4', 'wb') as f:
    f.write(b'\x00' * 1024 * 50)  # Overwrite with lots of zeroes to cause crash

Note: Never use this against others. Only test in an isolated lab.

Final Thoughts: Why This Matters

Anyone who uses Windows and watches videos—even offline!—could be at risk if they haven’t updated their HEVC Video Extensions. With video sharing so common, the potential for drive-by attacks is real.

Timeline

Published on: 03/09/2022 17:15:00 UTC
Last modified on: 03/14/2022 15:54:00 UTC