Protecting your 9040-MR9, 9080-M9S servers against “Spectre” and “Meltdown”

Protect your 9040-MR9, 9080-M9S servers from “Spectre” and “Meltdown” vulnerabilities.

Introduction

Four security vulnerabilities that allow unauthorized users to bypass the hardware barrier between applications and kernel memory were made public earlier this year. These vulnerabilities make use of speculative execution to perform side-channel information disclosure attacks.

The first three vulnerabilities, CVE-2017-5753 and CVE-2017- 5715 (collectively known as Spectre) and CVE-2018-3639 (known as Speculative Store Bypass) allow user or kernel-level code to infer data from unauthorized memory.

The fourth vulnerability, CVE-2017-5754 (known as Meltdown), allows user-level code to infer the contents of kernel memory.

The vulnerabilities are all variants of the same class of attacks but differ in the way that speculative execution could be exploited.

While these vulnerabilities do not allow an external unauthorized party to gain access to a machine, they could allow a party with access to a system to access unauthorized data.

Since the customer-specific operating environments, including system (including use of hypervisors) application, and operating systems are varied, POWER9™ systems (9040-MR9, 9080-M9S) provide the option for customers to control speculative execution at a system level, to meet their individual security standards.

Options for speculative execution control on 9040-MR9, 9080-M9S systems are as follows.
  1. Speculative execution controls to mitigate user-to-kernel and user-to-user side-channel attacks
  2. Speculative execution fully enabled

Speculative execution controls to mitigate user-to-kernel and user-to-user side-channel attacks

This mode is designed for systems that need to mitigate exposures of the hypervisor, operating systems, and user application data to untrusted code. For the 9040-MR9, 9080-M9S models this mode is set as the default.

Speculative execution fully enabled

This optional mode is designed for systems where the hypervisor, operating system, and applications can be fully trusted.
Note: Enabling this option could expose the system to CVE-2017-5753, CVE-2017- 5715, and CVE-2017-5754. This includes any partitions that are migrated (by using Live Partition Mobility) to this system.

Accessing speculative execution control options

Speculative execution control options can be accessed using the Advanced Systems Management Interface (ASMI) menu under System Configuration > Speculative Execution Control. This setting can be changed when the system is in powered off state.