RHEL 8 must disable the stream control transmission protocol (SCTP).

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-230496	RHEL-08-040023	SV-230496r792917_rule		Low

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. Failing to disconnect unused protocols can result in a system compromise. The Stream Control Transmission Protocol (SCTP) is a transport layer protocol, designed to support the idea of message-oriented communication, with several streams of messages within one connection. Disabling SCTP protects the system against exploitation of any flaws in its implementation.

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. Failing to disconnect unused protocols can result in a system compromise. The Stream Control Transmission Protocol (SCTP) is a transport layer protocol, designed to support the idea of message-oriented communication, with several streams of messages within one connection. Disabling SCTP protects the system against exploitation of any flaws in its implementation.

STIG	Date
Red Hat Enterprise Linux 8 Security Technical Implementation Guide	2022-09-07

Details

Check Text ( C-33165r792915_chk )
Verify the operating system disables the ability to load the SCTP kernel module. $ sudo grep -r sctp /etc/modprobe.d/* \| grep "/bin/true" install sctp /bin/true If the command does not return any output, or the line is commented out, and use of the SCTP is not documented with the Information System Security Officer (ISSO) as an operational requirement, this is a finding. Verify the operating system disables the ability to use the SCTP. Check to see if the SCTP is disabled with the following command: $ sudo grep -r sctp /etc/modprobe.d/* \| grep "blacklist" blacklist sctp If the command does not return any output or the output is not "blacklist sctp", and use of the SCTP is not documented with the Information System Security Officer (ISSO) as an operational requirement, this is a finding.

Check Text ( C-33165r792915_chk )

Verify the operating system disables the ability to load the SCTP kernel module.

$ sudo grep -r sctp /etc/modprobe.d/* | grep "/bin/true"

install sctp /bin/true

If the command does not return any output, or the line is commented out, and use of the SCTP is not documented with the Information System Security Officer (ISSO) as an operational requirement, this is a finding.

Verify the operating system disables the ability to use the SCTP.

Check to see if the SCTP is disabled with the following command:

$ sudo grep -r sctp /etc/modprobe.d/* | grep "blacklist"

blacklist sctp

If the command does not return any output or the output is not "blacklist sctp", and use of the SCTP is not documented with the Information System Security Officer (ISSO) as an operational requirement, this is a finding.

Fix Text (F-33140r792916_fix)
Configure the operating system to disable the ability to use the SCTP kernel module. Add or update the following lines in the file "/etc/modprobe.d/blacklist.conf": install sctp /bin/true blacklist sctp Reboot the system for the settings to take effect.