AlmaLinux OS 9 must disable the Stream Control Transmission Protocol (SCTP) kernel module.

Severity	Group ID	Group Title	Version	Rule ID	Date	STIG Version
medium	V-269345	SRG-OS-000095-GPOS-00049	ALMA-09-030050	SV-269345r1050227_rule	2025-02-20	1

Description
The 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.

ℹ️ Check
Verify that AlmaLinux OS 9 disables the ability to load the SCTP kernel module with the following command: $ grep -r sctp /etc/modprobe.conf /etc/modprobe.d/* /etc/modprobe.d/sctp.conf:install sctp /bin/false /etc/modprobe.d/sctp.conf:blacklist sctp If the command does not return any output, or the line is commented out, and use of SCTP is not documented with the information system security officer (ISSO) as an operational requirement, this is a finding.

ℹ️ Check

Verify that AlmaLinux OS 9 disables the ability to load the SCTP kernel module with the following command: $ grep -r sctp /etc/modprobe.conf /etc/modprobe.d/* /etc/modprobe.d/sctp.conf:install sctp /bin/false /etc/modprobe.d/sctp.conf:blacklist sctp If the command does not return any output, or the line is commented out, and use of SCTP is not documented with the information system security officer (ISSO) as an operational requirement, this is a finding.

✔️ Fix
To configure the system to prevent the SCTP kernel module from being loaded, run the following command: $ cat << EOF \| tee /etc/modprobe.d/sctp.conf install sctp /bin/false blacklist sctp EOF