Ubuntu 22.04 LTS must be configured to use TCP syncookies.
An XCCDF Rule
Description
<VulnDiscussion>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.</VulnDiscussion><FalsePositives></FalsePositives><FalseNegatives></FalseNegatives><Documentable>false</Documentable><Mitigations></Mitigations><SeverityOverrideGuidance></SeverityOverrideGuidance><PotentialImpacts></PotentialImpacts><ThirdPartyTools></ThirdPartyTools><MitigationControl></MitigationControl><Responsibility></Responsibility><IAControls></IAControls>
- ID
- SV-260522r958528_rule
- Severity
- Medium
- References
- Updated
Remediation - Manual Procedure
Configure Ubuntu 22.04 LTS to use TCP syncookies by using the following command:
$ sudo sysctl -w net.ipv4.tcp_syncookies = 1
If "1" is not the system's default value, add or update the following line in "/etc/sysctl.conf":