+CM-07 [H] Least Functionality
---+CM-07(01) [H] Periodic Review
---+CM-07(02) [H] Prevent Program Execution
---+CM-07(05) [H] Authorized Software — Allow-by-exception

CM-07 [H] Least Functionality

Control

  1. Configure the system to provide only [Assignement: mission-essential capabilities] ; and
  2. Prohibit or restrict the use of the following functions, ports, protocols, software, and/or services: [Assignement: organization-defined prohibited or restricted functions, system ports, protocols, software, and/or services].

Discussion

Systems 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. Additionally, it is sometimes convenient to provide multiple services from a single system component, but doing so increases risk over limiting the services provided by that single component. Where feasible, organizations limit component functionality to a single function per component. Organizations consider removing unused or unnecessary software and disabling unused or unnecessary physical and logical ports and protocols to prevent unauthorized connection of components, transfer of information, and tunneling. Organizations employ network scanning tools, intrusion detection and prevention systems, and end-point protection technologies, such as firewalls and host-based intrusion detection systems, to identify and prevent the use of prohibited functions, protocols, ports, and services. Least functionality can also be achieved as part of the fundamental design and development of the system (see [SA-8](#sa-8), [SC-2](#sc-2) , and [SC-3](#sc-3)).

Assessment Objective

  1. the system is configured to provide only [Assignement: mission-essential capabilities];
    1. the use of [Assignement: functions] is prohibited or restricted;
    2. the use of [Assignement: ports] is prohibited or restricted;
    3. the use of [Assignement: protocols] is prohibited or restricted;
    4. the use of [Assignement: software] is prohibited or restricted;
    5. the use of [Assignement: services] is prohibited or restricted.

Assessment Method

Examine

Configuration management policy procedures addressing least functionality in the system configuration management plan system design documentation system configuration settings and associated documentation system component inventory common secure configuration checklists system security plan other relevant documents or records

Interview

Organizational personnel with security configuration management responsibilities organizational personnel with information security responsibilities system/network administrators system developers

1. Übersicht

CM-07(01) [H] Periodic Review

Control

  1. Review the system [Assignement: frequency] to identify unnecessary and/or nonsecure functions, ports, protocols, software, and services; and
  2. Disable or remove [Assignement: organization-defined functions, ports, protocols, software, and services within the system deemed to be unnecessary and/or nonsecure].

Discussion

Organizations review functions, ports, protocols, and services provided by systems or system components to determine the functions and services that are candidates for elimination. Such reviews are especially important during transition periods from older technologies to newer technologies (e.g., transition from IPv4 to IPv6). These technology transitions may require implementing the older and newer technologies simultaneously during the transition period and returning to minimum essential functions, ports, protocols, and services at the earliest opportunity. Organizations can either decide the relative security of the function, port, protocol, and/or service or base the security decision on the assessment of other entities. Unsecure protocols include Bluetooth, FTP, and peer-to-peer networking.

Assessment Objective

  1. the system is reviewed [Assignement: frequency] to identify unnecessary and/or non-secure functions, ports, protocols, software, and services:
    1. [Assignement: functions] deemed to be unnecessary and/or non-secure are disabled or removed;
    2. [Assignement: ports] deemed to be unnecessary and/or non-secure are disabled or removed;
    3. [Assignement: protocols] deemed to be unnecessary and/or non-secure are disabled or removed;
    4. [Assignement: software] deemed to be unnecessary and/or non-secure is disabled or removed;
    5. [Assignement: services] deemed to be unnecessary and/or non-secure are disabled or removed.

Assessment Method

Examine

Configuration management policy procedures addressing least functionality in the system configuration management plan system design documentation system configuration settings and associated documentation common secure configuration checklists documented reviews of functions, ports, protocols, and/or services change control records system audit records system security plan other relevant documents or records

Interview

Organizational personnel with responsibilities for reviewing functions, ports, protocols, and services on the system organizational personnel with information security responsibilities system/network administrators system developers
CM-07(02) [H] Prevent Program Execution

Control

Prevent program execution in accordance with [Selection(one-or-more): {{ insert: param, cm-07.02_odp.02 }} ; rules authorizing the terms and conditions of software program usage].

Discussion

Prevention of program execution addresses organizational policies, rules of behavior, and/or access agreements that restrict software usage and the terms and conditions imposed by the developer or manufacturer, including software licensing and copyrights. Restrictions include prohibiting auto-execute features, restricting roles allowed to approve program execution, permitting or prohibiting specific software programs, or restricting the number of program instances executed at the same time.

Assessment Objective

program execution is prevented in accordance with [Selection(one-or-more): {{ insert: param, cm-07.02_odp.02 }} ; rules authorizing the terms and conditions of software program usage].

Assessment Method

Examine

Configuration management policy procedures addressing least functionality in the system configuration management plan system design documentation system configuration settings and associated documentation system component inventory common secure configuration checklists specifications for preventing software program execution change control records system audit records system security plan other relevant documents or records

Interview

Organizational personnel with information security responsibilities system/network administrators system developers
CM-07(05) [H] Authorized Software — Allow-by-exception

Control

  1. Identify [Assignement: software programs];
  2. Employ a deny-all, permit-by-exception policy to allow the execution of authorized software programs on the system; and
  3. Review and update the list of authorized software programs [Assignement: frequency].

Discussion

Authorized software programs can be limited to specific versions or from a specific source. To facilitate a comprehensive authorized software process and increase the strength of protection for attacks that bypass application level authorized software, software programs may be decomposed into and monitored at different levels of detail. These levels include applications, application programming interfaces, application modules, scripts, system processes, system services, kernel functions, registries, drivers, and dynamic link libraries. The concept of permitting the execution of authorized software may also be applied to user actions, system ports and protocols, IP addresses/ranges, websites, and MAC addresses. Organizations consider verifying the integrity of authorized software programs using digital signatures, cryptographic checksums, or hash functions. Verification of authorized software can occur either prior to execution or at system startup. The identification of authorized URLs for websites is addressed in [CA-3(5)](#ca-3.5) and [SC-7](#sc-7).

Assessment Objective

  1. [Assignement: software programs] are identified;
  2. a deny-all, permit-by-exception policy to allow the execution of authorized software programs on the system is employed;
  3. the list of authorized software programs is reviewed and updated [Assignement: frequency].

Assessment Method

Examine

Configuration management policy procedures addressing least functionality in the system configuration management plan system design documentation system configuration settings and associated documentation list of software programs authorized to execute on the system system component inventory common secure configuration checklists review and update records associated with list of authorized software programs change control records system audit records system security plan other relevant documents or records

Interview

Organizational personnel with responsibilities for identifying software authorized to execute on the system organizational personnel with information security responsibilities system/network administrators

1.1 Referenzen

1.2 Identifizierte Anforderungen

1.3 Zugehörige Regulierungen

2. Identifizierte Anforderungen

Anforderungen

3. Zugehörige Regulierungen

Regulierungen

Verknüpfte Vorgänge

Verknüpfungen
is blocked by CM-07 [H] Least Functionality – Assessment Procedure
is blocked by Least Functionality