Only if you already have the ability to read arbitrary RAM. So running in kernel/hypervisor mode. The exploit is being able to do it from usermode through an a

Only if you already have the ability to read arbitrary RAM. So running in kernel/hypervisor mode. The exploit is being able to do it from usermode through an api (browser/js) that normally forbids that. Userspace can only access its own memory, rather than the whole systems.