UBTU-22-251025 - Ubuntu 22.04 LTS must configure the Uncomplicated Firewall (ufw) to rate-limit impacted network interfaces.

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Information

Denial of service (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.

This requirement addresses the configuration of the operating system to mitigate the impact of DoS attacks that have occurred or are ongoing on system availability. For each system, known and potential DoS attacks must be identified and solutions for each type implemented. A variety of technologies exist to limit or, in some cases, eliminate the effects of DoS attacks (e.g., limiting processes or establishing memory partitions). Employing increased capacity and bandwidth, combined with service redundancy, may reduce the susceptibility to some DoS attacks.

NOTE: Nessus has provided the target output to assist in reviewing the benchmark to ensure target compliance.

Solution

Configure the application firewall to protect against or limit the effects of DoS attacks by ensuring Ubuntu 22.04 LTS is implementing rate-limiting measures on impacted network interfaces.

For each service with a port listening to connections, run the following command, replacing '<service_name>' with the service that needs to be rate limited.

$ sudo ufw limit <service_name>

Rate-limiting can also be done on an interface. An example of adding a rate limit on the 'ens160' interface follows:

$ sudo ufw limit in on ens160

See Also

https://dl.dod.cyber.mil/wp-content/uploads/stigs/zip/U_CAN_Ubuntu_22-04_LTS_V2R1_STIG.zip

Item Details

References: CAT|II, CCI|CCI-002385, Rule-ID|SV-260517r958902_rule, STIG-ID|UBTU-22-251025, Vuln-ID|V-260517

Plugin: Unix

Control ID: ea9ed5e90c103c467b68b9aeb1b5e82a72e46ec292959e0912a338c439cafeab