An industry-wide issue was found in the way many modern microprocessor designs have implemented speculative execution of Load & Store instructions . It relies on the presence of a precisely-defined instruction sequence in the privileged code as well as the fact that memory read from address to which a recent memory write has occurred may see an older value and subsequently cause an update into the microprocessor's data cache even for speculatively executed instructions that never actually commit . As a result, an unprivileged attacker could use this flaw to read privileged memory by conducting targeted cache side-channel attacks.