3.4.6 has a weight of -5 points

(Configuration Management Family) 6/9

Employ the principle of least functionality by configuring organizational systems to provide only essential capabilities.

Video:

Example of Sysytem Security Plan (SSP):

    1. System Security Plan (SSP) – Control 3.4.6

      Control Title: Employ the Principle of Least Functionality

      Control Requirement: Configure organizational systems to provide only essential capabilities.

      Implementation Status: Implemented

      Implementation Details:

      1. Service-Level Controls:

        • All services within the organization operate without admin-level credentials. This ensures that even if a service is compromised, the potential damage is contained within the bounds of that service’s permissions.
        • Services are strictly designed and monitored to ensure they only offer required functionalities, reducing potential avenues of attack.

      2. Endpoint Management:

        • The organization leverages Active Directory with Group Policy to ensure granular control over system functionalities.
        • Controls are in place to dictate which applications can be installed, executed, and which internet destinations are accessible.
        • The endpoint management system effectively manages file system permissions, ensuring that users can only access the files they need for their respective duties.

      3. Access Based on Role:

        • Permissions are granted based solely on job requirements. If a role doesn’t necessitate access to specific data or functionality, that access is not granted.
        • Continuous auditing and review processes are in place to ensure access permissions align with job duties and to revoke unnecessary access promptly.

      4. Physical Premise Access Control:

        • The organization employs a stringent physical premise access control system.
        • Access to specific zones, like IT closets or server rooms, is limited only to personnel whose roles necessitate it.
        • Unauthorized access to sensitive areas is detected and promptly acted upon to ensure the physical security of IT resources.

    Example of Plan of Action and Milestones ( POA & M):

    Plan of Actions & Milestones (POA&M) – Control 3.4.6

    Milestone 1: Identification and Evaluation of Essential Functions and Services

    • Task 1: Review the functions and services provided by organizational systems or components by [Target Date].
    • Task 2: Identify functions and services essential for supporting organizational missions, functions, or operations.
    • Task 3: Identify functions and services that are candidates for elimination or disabling to adhere to the principle of least functionality.
    • Expected Completion for Milestone: [Target Date]

    Milestone 2: Configuration of Systems for Minimal Functionality

    • Task 1: Configure systems to provide only the necessary functions and services required for their intended purpose by [Target Date].
    • Task 2: Avoid the provision of multiple services from a single system component to minimize risk.
    • Task 3: Limit component functionality to a single function per component, where feasible, to enhance security and reduce potential vulnerabilities.
    • Expected Completion for Milestone: [Target Date]

    Milestone 3: Disabling of Unused or Unnecessary Ports and Protocols

    • Task 1: Disable unused or unnecessary physical and logical ports and protocols by [Target Date].
    • Task 2: Utilize network scanning tools to identify prohibited functions, ports, protocols, and services.
    • Task 3: Implement intrusion detection and prevention systems to detect and prevent the use of unauthorized capabilities.
    • Expected Completion for Milestone: [Target Date]

    Milestone 4: Endpoint Protection and Security Measures

    • Task 1: Employ endpoint protections such as firewalls and host-based intrusion detection systems by [Target Date].
    • Task 2: Implement ongoing monitoring and maintenance processes to ensure adherence to the principle of least functionality.
    • Task 3: Conduct regular assessments and audits to verify system configurations and identify any deviations or vulnerabilities.
    • Expected Completion for Milestone: [Target Date]

    Milestone 5: Documentation and Monitoring

    • Task 1: Document configuration changes made to align with the principle of least functionality by [Target Date].
    • Task 2: Establish ongoing monitoring processes to ensure systems continue to adhere to the principle of least functionality.
    • Task 3: Promptly address any new or emerging security risks identified during monitoring.
    • Expected Completion for Milestone: [Target Date]

    Monitoring and Reporting: Progress on the POA&M will be reviewed monthly, with adjustments made to timelines and actions as necessary. Quarterly reports will be submitted to leadership to ensure visibility and accountability in addressing these milestones and tasks.

     

    RELEVANT INFORMATION:

    Systems can provide a wide variety of functions and services. Some of the functions and services routinely provided by default, may not be necessary to support essential organizational missions, functions, or operations. It is sometimes convenient to provide multiple services from single system components. However, doing so increases risk over limiting the services provided by any one component. Where feasible, organizations limit component functionality to a single function per component. Organizations review functions and services provided by systems or components of systems, to determine which functions and services are candidates for elimination. Organizations disable unused or unnecessary physical and logical ports and protocols to prevent unauthorized connection of devices, transfer of information, and tunneling. Organizations can utilize network scanning tools, intrusion detection and prevention systems, and end-point protections such as firewalls and host-based intrusion detection systems to identify and prevent the use of prohibited functions, ports,

    protocols, and services.



    Resources to consider:

    Security Policy Document:

    This comprehensive document outlines the organization’s security policies and procedures, including information system access controls and the specific measures implemented, such as password protection, multi-factor authentication, and device access controls. It should also cover consequences of unauthorized access and the importance of user training and awareness.

    Asset Inventory and Access Control Sheet:

    Create a spreadsheet that lists all information system resources in your organization, such as laptops, desktops, servers, network devices, printers, scanners, mobile devices, and paper documents. Alongside each resource, include information about authorized users, access rights, and any access restrictions.

    User Account Management Log:

    Maintain a log to track user account creation, modification, and removal. Include details like the date of account creation, purpose, and the individual responsible for approving the account.

    Password and Multi-Factor Authentication Policy:

    Combine the password policy and multi-factor authentication policy into a single document. Outline the organization’s password requirements, including complexity, length, expiration, and regular password change, as well as the implementation of multi-factor authentication for an extra layer of security.

    Process and Script Accountability Log:

    Maintain a log that associates automated scripts and processes with the specific authorized user who initiated them. This ensures accountability and prevents the use of generic accounts for critical processes.

    Device Access Control and VPN Policy:

    Merge the device access control and VPN configuration documents into a single policy. Detail the measures for controlling device access, authentication mechanisms, and VPN configuration, including which devices are allowed to connect and the authentication methods used.

    Access Control Review and Monitoring Schedule:

    Create a schedule for periodic reviews of access controls, including the process for adding, modifying, or revoking access rights based on personnel changes or business needs. Also, document the monitoring mechanisms implemented to track access to the information system, including logs and reports of access attempts and unusual activities.

    User Training and Awareness Materials:

    Prepare training materials and conduct regular sessions for authorized users. Document the topics covered, the date of the training, and the attendees.