Details

Ubuntu operating system management includes the ability to control the number of users and user sessions that utilize an Ubuntu operating system. Limiting the number of allowed users and sessions per user is helpful in reducing the risks related to DoS attacks.

This requirement addresses concurrent sessions for information system accounts and does not address concurrent sessions by single users via multiple system accounts. The maximum number of concurrent sessions should be defined based upon mission needs and the operational environment for each system.

Solution

Configure the Ubuntu operating system to limit the number of concurrent sessions to ten for all accounts and/or account types.

Add the following line to the top of the /etc/security/limits.conf:

* hard maxlogins 10

Supportive Information

The following resource is also helpful.

• https://dl.dod.cyber.mil/wp-content/uploads/stigs/zip/U_CAN_Ubuntu_16-04_LTS_V2R3_STIG.zip

This security hardening control applies to the following category of controls within NIST 800-53: Access Control.This control applies to the following type of system Unix.

References

• 800-53|AC-10
• CAT|III
• CCI|CCI-000054
• Rule-ID|SV-214946r610931_rule
• STIG-ID|UBTU-16-010070
• STIG-Legacy|SV-90123
• STIG-Legacy|V-75443
• Vuln-ID|V-214946

Source

• Tenable.com/audits