If your WhatsApp app and phone's operating system (Android/iOS) are up to date , these specific older vulnerabilities are patched and no longer a threat.
Can't download, open, or send media files | WhatsApp Help Center VID-20221228-WA0279.mp4
If you are "looking into" this file due to security concerns or because it won't open, here is the relevant technical and safety information: 🛡️ Security Concerns: Malware & Exploits If your WhatsApp app and phone's operating system
A high-severity flaw once allowed attackers to execute code via a malicious MP4. VID-20221228-WA0279.mp4
If the video came from an unknown sender or looks suspicious, it is safest to delete it without opening it.
There have been historical cases where hackers used specially crafted on WhatsApp to trigger security vulnerabilities.