RHEL 8 must disable access to network bpf syscall from unprivileged processes.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-230545	RHEL-08-040281	SV-230545r627750_rule		Medium

Description
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.

STIG	Date
Red Hat Enterprise Linux 8 Security Technical Implementation Guide	2021-03-04

Details

Check Text ( C-33214r568381_chk )
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 Text (F-33189r568382_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