Title

The operating system must manage excess capacity, bandwidth, or other redundancy to limit the effects of information flooding types of Denial of Service (DoS) attacks. (Cat II impact)

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. Satisfies: SRG-OS-000142-GPOS-00071

Check Content

Verify the operating system manages excess capacity, bandwidth, or other redundancy to limit the effects of information flooding types of Denial of Service (DoS) attacks. If it does not, this is a finding. The status of the "net.inet.tcp.syncookies" kernel parameter can be queried by running the following command: $ sysctl net.inet.tcp.syncookies The output of the command should indicate a value of "1". If this value is not "1", investigate how it could have been aduusted at runtime, and verify it is not set improperly in "/etc/sysctl.conf". $ grep net.inet.tcp.syncookies /etc/sysctl.conf If an incorrect value is returned by sysctl, or configured improperly in /etc/sysctl.conf, this is a finding.

Fix Text

Configure the operating system to manage excess capacity, bandwidth, or other redundancy to limit the effects of information flooding types of Denial of Service (DoS) attacks.

Additional Identifiers

Rule ID:

Vulnerability ID: V-710

Group Title:

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.