It’s true for any variation of Linux. Hell, the vulnerability (Mimikatz) that was crucial in the most expensive cyber security attack in history is still there in Windows.
And for X11 to be exploited you would need to get and run malicious code in the first place. The Linux security model kicks in before you get to that point.
This site seems suspicious as hell. Incredibly basic site, no info on where they’re located, and the “About Us” links aren’t even links. There’s no About Us page.