documentation_complete: true

title: 'Enable TCP/IP syncookie support'

description: |-
    Normal TCP/IP networking is open to an attack known as SYN flooding.
    It is denial-of-service attack that prevents legitimate remote users from being able to connect
    to your computer during an ongoing attack.

    When enabled the TCP/IP stack will use a cryptographic challenge protocol known as SYN cookies
    to enable legitimate users to continue to connect, even when your machine is under attack.

    {{{ describe_kernel_build_config("CONFIG_SYN_COOKIES", "y") | indent(4) }}}

rationale: |-
    SYN cookies provide protection against SYN flooding attacks.

warnings:
    {{{ warning_kernel_build_config() | indent(4) }}}

severity: medium

identifiers:
    cce@rhel8: CCE-87330-7
    cce@rhel9: CCE-87331-5
    cce@rhel10: CCE-89322-2

ocil_clause: 'the kernel was not built with the required value'

ocil: |-
    {{{ ocil_kernel_build_config("CONFIG_SYN_COOKIES", "y") | indent(4) }}}

template:
    name: kernel_build_config
    vars:
        config: CONFIG_SYN_COOKIES
        value: 'y'

