It was discovered that microprocessors utilizing speculative execution and branch prediction may allow unauthorized memory reads via sidechannel attacks. This flaw is known as Spectre. A local attacker could use this to expose sensitive information, including kernel memory. (CVE-2017-5715)
This update provides the microcode updates required for the corresponding Linux kernel updates.
3.20180108.0~ubuntu14.04.23.20180108.0~ubuntu16.04.2