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V-282630

CAT II (Medium)

TOSS 5 must prevent loading a new kernel for later execution.

Rule ID

SV-282630r1200870_rule

STIG

Tri-Lab Operating System Stack (TOSS) 5 Security Technical Implementation Guide

Version

V1R1

CCIs

CCI-000366

Discussion

Changes to any software components can have significant effects on the overall security of the operating system. This requirement ensures the software has not been tampered with and that it has been provided by a trusted vendor. Disabling "kexec_load" prevents an unsigned kernel image (that could be a windows kernel or modified vulnerable kernel) from being loaded. Kexec can be used subvert the entire secureboot process and should be avoided at all costs especially since it can load unsigned kernel images.

Check Content

Verify TOSS 5 is configured to disable kernel image loading using the following command:

$ sudo sysctl kernel.kexec_load_disabled

kernel.kexec_load_disabled = 1

If "kernel.kexec_load_disabled" is not set to "1" or is missing, this is a finding.

Fix Text

Add or edit the following line in a system configuration file in the "/etc/sysctl.d/" directory:

kernel.kexec_load_disabled = 1

Load settings from all system configuration files using the following command:

$ sudo sysctl --system