He says the problem with the prefetcher on the Apple M-series chips exists because unlike other prefetchers in other chips that only examine addresses, the prefetcher in the Apple chips are programmed to also look at values stored inside addresses and this therefore puts them in the vulnerable position of confusing a value with an address and placing it into the cache. It’s also theoretically possible for an attacker to pull this off by embedding malicious code into Javascript on a web site so that when a computer with an M-series chip visits the site, the attacker’s malicious code can conduct the attack to grab data from the cache.