RHEL 8 must enable hardening for the Berkeley Packet Filter Just-in-time compiler.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-244554	RHEL-08-040286	SV-244554r743911_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. Enabling hardening for the Berkeley Packet Filter (BPF) Just-in-time (JIT) compiler aids in mitigating JIT spraying attacks. Setting the value to "2" enables JIT hardening for all users.

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. Enabling hardening for the Berkeley Packet Filter (BPF) Just-in-time (JIT) compiler aids in mitigating JIT spraying attacks. Setting the value to "2" enables JIT hardening for all users.

STIG	Date
Red Hat Enterprise Linux 8 Security Technical Implementation Guide	2021-06-14

Details

Check Text ( C-47829r743909_chk )
Verify RHEL 8 enables hardening for the BPF JIT with the following commands: $ sudo sysctl net.core.bpf_jit_harden net.core.bpf_jit_harden = 2 If the returned line does not have a value of "2", or a line is not returned, this is a finding.

Fix Text (F-47786r743910_fix)
Configure RHEL 8 to enable hardening for the BPF JIT compiler by adding the following line to a file in the "/etc/sysctl.d" directory: net.core.bpf_jit_harden = 2 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