Amazon Linux 2023 must manage excess capacity, bandwidth, or other redundancy to limit the effects of information flooding types of denial-of-service (DoS) attacks.

STIG ID: AZLX-23-001090  |  SRG: SRG-OS-000142-GPOS-00071 |  Severity: medium (CAT II)  |  CCI: CCI-001095 |  Vulnerability Id: V-274030

Vulnerability Discussion

DoS is a condition when a resource is not available for legitimate users. When this occurs, the organization either cannot accomplish its mission or must operate at degraded capacity.

Managing excess capacity ensures that sufficient capacity is available to counter flooding attacks. Employing increased capacity and service redundancy may reduce the susceptibility to some DoS attacks. Managing excess capacity may include, for example, establishing selected usage priorities, quotas, or partitioning.

Check

Verify Amazon Linux 2023 manages excess capacity, bandwidth, or other redundancy to limit the effects of information flooding types of DoS attacks.

Verify nftables is configured to allow rate limits on any connection to the system with the following command:

$ sudo grep -i firewallbackend /etc/firewalld/firewalld.conf
FirewallBackend=nftables

Fix

Configure Amazon Linux 2023 to manage excess capacity, bandwidth, or other redundancy to limit the effects of information flooding types of DoS attacks.

Configure "nftables" to be the default "firewallbackend" for "firewalld" by adding or editing the following line in "etc/firewalld/firewalld.conf":

FirewallBackend=nftables

Establish rate-limiting rules based on organization-defined types of DoS attacks on impacted network interfaces.