Vulnerability Discussion

It is detrimental for operating systems to provide, or install by default, functionality exceeding requirements or mission objectives. These unnecessary capabilities or services are often overlooked and therefore may remain unsecured. They increase the risk to the platform by providing additional attack vectors.

Check

Verify RHEL 8 prevents privilege escalation thru the kernel by disabling access to the bpf syscall with the following commands:

$ sudo sysctl kernel.unprivileged_bpf_disabled

kernel.unprivileged_bpf_disabled = 1

If the returned line does not have a value of "1", or a line is not returned, this is a finding.

Fix

Configure RHEL 8 to prevent privilege escalation thru the kernel by disabling access to the bpf syscall by adding the following line to a file in the "/etc/sysctl.d" directory:

kernel.unprivileged_bpf_disabled = 1

The system configuration files need to be reloaded for the changes to take effect. To reload the contents of the files, run the following command:

$ sudo sysctl --system