Deathray Browser Attack Proves Mac GPU Drivers Are Still Vulnerable
Auberon's day job is as an instructor at the Green River College in Auburn, Washington, but Auberon still found time to document and detail "Deathray" on an interactive web page that includes a working demonstration of the vulnerability.
So, what exactly is Deathray doing that can freeze a Mac system? It's forcing a shader through the WebGPU driver that contains an infinite loop, which copies the same vector over and over. What happens next can vary from losing input, to getting the loading "beach ball," to magenta GPU artifacts appearing onscreen. Eventually, the issues trigger a kernel panic that restarts the Mac.
But the reason it has remained obscure for all of this time is the same reason you're unlikely to see it in the wild: it doesn't do anything helpful for an attacker. These days, malware that slows a system is usually being used as part of a botnet, often for mining cryptocurrency. Meanwhile, attacks like FROST or ASCII smuggling exist to exfiltrate sensitive information.
Deathray neither steals data nor grants control of the system--it's just exploiting an bug in Apple's WebGPU implementation. The age and known status of the vulnerability does bring into question whether or not it can be patched, but we imagine if it ever does happen, it'll be soon now that there's increased awareness of it. Otherwise, its ultra-niche status and lack of applicability beyond simply antagonizing the victim make Deathray unlikely to be a problem for most users.
