The Spectre vulnerability (CVE-2017-5753 and CVE-2017-5715) is a hardware-based vulnerability that affects modern microprocessors and can be exploited by attackers to access sensitive information, such as passwords and encryption keys. To patch the Spectre vulnerability on Linux, you will need to install the latest microcode update from your processor vendor and update your operating system.
For example, on Red Hat Enterprise Linux (RHEL) and CentOS, you can check the installed microcode version by using the dmesg command. To update the microcode, you can run the following command as root:
yum update microcode_ctl
You will also need to update your Linux kernel to a version that contains the necessary patches to address the Spectre vulnerability. This can be done by using the following command on RHEL/CentOS:
yum update kernel
After updating the microcode and kernel, you should reboot your system for the changes to take effect. To verify if your system is protected against Spectre, you can use the spectre-meltdown-checker script, which is a shell script that checks for the presence of the Spectre and Meltdown vulnerabilities on Linux systems.