Overview

Security Requirements for 03.13.09 Connections Termination

This requirement applies to internal and external networks. Terminating network connections associated with communications sessions include de-allocating associated TCP/IP address or port pairs at the operating system level, or de-allocating networking assignments at the application level if multiple application sessions are using a single, operating system-level network connection. Time periods of user inactivity may be established by organizations and include time periods by type of network access or for specific network accesses.

Assessment GuidanceExamine 0/7

How an assessor determines this requirement is met. Source: CMMC Assessment Guide – Level 2, Version 2.13 (NIST SP 800-171 Rev. 2).

Discussion

Prevent malicious actors from taking advantage of an open network session or an unattended computer at the end of the connection. Balance user work patterns and needs against security to determine the length of inactivity that will force a termination.

This requirement, SC.L2-3.13.9, specifies network connections be terminated under certain conditions, which complements AC.L2-3.1.18 that specifies control of mobile device connections.

Examples

  1. Example 1

    You are an administrator of a server that provides remote access. Your company’s policies state that network connections must be terminated after being idle for 60 minutes [a]. You edit the server configuration file and set the timeout to 60 minutes and restart the remote access software [c]. You test the software and verify that the connection is terminated appropriately.

Assessment Methods

Examine
The process of reviewing, inspecting, observing, studying, or analyzing assessment objects (e.g., policies, procedures, plans, system designs, mechanisms) to facilitate understanding, achieve clarification, or obtain evidence.Example: An assessor reads the access control policy and inspects system configuration settings to confirm they match.

Not all of the evidence listed is required to meet this requirement — check the items your organization has collected.

Interview
The process of holding discussions with individuals or groups within an organization to facilitate understanding, achieve clarification, or identify the location of evidence.Example: An assessor asks a system administrator to describe how user accounts are approved, reviewed, and disabled.
  • System or network administrators
  • Personnel with information security responsibilities
  • System developer
Test
The process of exercising assessment objects (e.g., activities, mechanisms) under specified conditions to compare actual behavior with expected behavior.Example: An assessor attempts to sign in with a disabled account to confirm that access is denied.
  • Mechanisms supporting or implementing network disconnect capability

Potential Assessment Considerations

  • Are the network connections requiring management and time-out for inactivity documented [a]?
  • Are the network connections requiring management and time-out for inactivity configured and implemented [c]?

Key References

NIST SP 800-171 Rev. 2 3.13.9

Evidence

  1. 03.13.09.a

    A period of inactivity to terminate network connections associated with communications sessions is defined

  1. 03.13.09.b

    Network connections associated with communications sessions are terminated at the end of the sessions

  1. 03.13.09.c

    Network connections associated with communications sessions are terminated after the defined period of inactivity