3.13: System and Communications Protection

Communications can be monitored, controlled, and protected at boundary components and by restricting or prohibiting interfaces in organizational systems. Boundary components include gateways, routers, firewalls, guards, network-based malicious code analysis and virtualization systems, or encrypted tunnels implemented within a system security architecture (e.g., routers protecting firewalls or application gateways residing on protected subnetworks). Restricting or…

Organizations apply systems security engineering principles to new development systems or systems undergoing major upgrades. For legacy systems, organizations apply systems security engineering principles to system upgrades and modifications to the extent feasible, given the current state of hardware, software, and firmware components within those systems. The application of systems security engineering concepts and principles…

System management functionality includes functions necessary to administer databases, network components, workstations, or servers, and typically requires privileged user access. The separation of user functionality from system management functionality is physical or logical. Organizations can implement separation of system management functionality from user functionality by using different computers, different central processing units, different instances of…

The control of information in shared system resources (e.g., registers, cache memory, main memory, hard disks) is also commonly referred to as object reuse and residual information protection. This requirement prevents information produced by the actions of prior users or roles (or the actions of processes acting on behalf of prior users or roles) from…

Subnetworks that are physically or logically separated from internal networks are referred to as demilitarized zones (DMZs). DMZs are typically implemented with boundary control devices and techniques that include routers, gateways, firewalls, virtualization, or cloud-based technologies. [SP 800-41] provides guidance on firewalls and firewall policy. [SP 800-125B] provides guidance on security for virtualization technologies.

This requirement applies to inbound and outbound network communications traffic at the system boundary and at identified points within the system. A deny-all, permit-by-exception network communications traffic policy ensures that only those connections which are essential and approved are allowed.

Split tunneling might be desirable by remote users to communicate with local system resources such as printers or file servers. However, split tunneling allows unauthorized external connections, making the system more vulnerable to attack and to exfiltration of organizational information. This requirement is implemented in remote devices (e.g., notebook computers, smart phones, and tablets) through…

This requirement applies to internal and external networks and any system components that can transmit information including servers, notebook computers, desktop computers, mobile devices, printers, copiers, scanners, and facsimile machines. Communication paths outside the physical protection of controlled boundaries are susceptible to both interception and modification. Organizations relying on commercial providers offering transmission services as…

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…

Cryptographic key management and establishment can be performed using manual procedures or mechanisms supported by manual procedures. Organizations define key management requirements in accordance with applicable federal laws, Executive Orders, policies, directives, regulations, and standards specifying appropriate options, levels, and parameters. [SP 800-56A] and [SP 800-57-1] provide guidance on cryptographic key management and key establishment.

Cryptography can be employed to support many security solutions including the protection of controlled unclassified information, the provision of digital signatures, and the enforcement of information separation when authorized individuals have the necessary clearances for such information but lack the necessary formal access approvals. Cryptography can also be used to support random number generation and…

Collaborative computing devices include networked white boards, cameras, and microphones. Indication of use includes signals to users when collaborative computing devices are activated. Dedicated video conferencing systems, which rely on one of the participants calling or connecting to the other party to activate the video conference, are excluded.

Mobile code technologies include Java, JavaScript, ActiveX, Postscript, PDF, Flash animations, and VBScript. Decisions regarding the use of mobile code in organizational systems are based on the potential for the code to cause damage to the systems if used maliciously. Usage restrictions and implementation guidance apply to the selection and use of mobile code installed…

VoIP has different requirements, features, functionality, availability, and service limitations when compared with the Plain Old Telephone Service (POTS) (i.e., the standard telephone service). In contrast, other telephone services are based on high-speed, digital communications lines, such as Integrated Services Digital Network (ISDN) and Fiber Distributed Data Interface (FDDI). The main distinctions between POTS and…

Authenticity protection includes protecting against man-in-the-middle attacks, session hijacking, and the insertion of false information into communications sessions. This requirement addresses communications protection at the session versus packet level (e.g., sessions in service-oriented architectures providing web-based services) and establishes grounds for confidence at both ends of communications sessions in ongoing identities of other parties and…

Information at rest refers to the state of information when it is not in process or in transit and is located on storage devices as specific components of systems. The focus of protection at rest is not on the type of storage device or the frequency of access but rather the state of the information.…