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.
A high-severity flaw once allowed attackers to execute code via a malicious MP4. VID-20221228-WA0279.mp4
Can't download, open, or send media files | WhatsApp Help Center If your WhatsApp app and phone's operating system
If the video came from an unknown sender or looks suspicious, it is safest to delete it without opening it. 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