Meltdown (which so far is proven to impact Intel whereas AMD's design appears to negate it pretty much entirely) is catastrophically practical to use. Meltdown

Meltdown (which so far is proven to impact Intel whereas AMD's design appears to negate it pretty much entirely) is catastrophically practical to use. Meltdown can read kernel memory at a rate of around 503 KB/s according to the paper. Not enough for a RAM dump probably, but if you can generally figure out what you want and where to look you've got plenty of bandwidth to dump it. All you need is code execution at any privilege level and an Intel host without the kernel workaround (so that's, what, ~95% of servers/desktops in the world currently?). Spectre appears far less significant in practice. The primary exploit target seems to be via JavaScript to snoop on the hosting browser process (aka, running untrusted code in your own process just became borderline impossible). If you're in your own process, though, being able to read other processes memory appears non-trivial. There wasn't any example of actually doing this in the paper, but it was speculated to be possible. The example code has the attacking code and the victim code in the same process (aka, you could also just get the secret by just reading it - the "attacker" had full read access to the memory to begin with). It was speculated that this could be done via IPC to get another process to inadvertently leak, but there was no PoC of this and given how much overhead (in terms of CPU time/instructions) there is in all forms of IPC I'm not sure how realistic that actually is in practice.