Google and Microsoft find a CPU security exploit - the solution may slow down your PC

Google and Microsoft have revealed a CPU security vulnerability which is similar to the Meltdown and Spectre flaws that were revealed earlier this year.

CPU hardware implementations—known as Spectre and Meltdown—are vulnerable to side-channel attacks. Meltdown is a bug that "melts" the security boundaries normally enforced by the hardware, affecting desktops, laptops, and cloud computers. Spectre is a flaw that an attacker can exploit to force a CPU to reveal its data.

The vulnerability called Speculative Store Bypass (SSB), also known as Variant 4 similarly exploits "speculative bypass". When exploited, Variant 4 could allow an attacker to read older memory values in a CPU’s stack or other memory locations.

According to Intel, “Most leading browser providers have recently deployed mitigations in their Managed Runtimes – mitigations that substantially increase the difficulty of exploiting side channels in a modern web browser. These techniques would likewise increase the difficulty of exploiting a side channel in a browser based on SSB.”