Limits on the use of organization-controlled portable storage devices in external systems include complete prohibition of the use of such devices or restrictions on how the devices may be used and under what conditions the devices may be used. Note that while “external” typically refers to outside of the organization’s direct supervision and authority, that is not always the case. Regarding the protection of CUI across an organization, the organization may have systems that process CUI and others that do not. Among the systems that process CUI there are likely access restrictions for CUI that apply between systems. Therefore, from the perspective of a given system, other systems within the organization may be considered “external" to that system.

In accordance with laws, Executive Orders, directives, policies, regulations, or standards, the public is not authorized access to nonpublic information (e.g., information protected under the Privacy Act, CUI, and proprietary information). This requirement addresses systems that are controlled by the organization and accessible to the public, typically without identification or authentication. Individuals authorized to post CUI onto publicly accessible systems are designated. The content of information is reviewed prior to posting onto publicly accessible systems to ensure that nonpublic information is not included.

Organizations determine the content and frequency of security awareness training and security awareness techniques based on the specific organizational requirements and the systems to which personnel have authorized access. The content includes a basic understanding of the need for information security and user actions to maintain security and to respond to suspected security incidents. The content also addresses awareness of the need for operations security. Security awareness techniques include: formal training; offering supplies inscribed with security reminders; generating email advisories or notices from organizational officials; displaying logon screen messages; displaying security awareness posters; and conducting information security awareness events. [SP 800-50] provides guidance on security awareness and training programs.

Organizations determine the content and frequency of security training based on the assigned duties, roles, and responsibilities of individuals and the security requirements of organizations and the systems to which personnel have authorized access. In addition, organizations provide system developers, enterprise architects, security architects, acquisition/procurement officials, software developers, system developers, systems integrators, system/network administrators, personnel conducting configuration management and auditing activities, personnel performing independent verification and validation, security assessors, and other personnel having access to system-level software, security-related technical training specifically tailored for their assigned duties. Comprehensive role-based training addresses management, operational, and technical roles and responsibilities covering physical, personnel, and technical controls. Such training can include policies, procedures, tools, and artifacts for the security roles defined. Organizations also provide the training necessary for individuals to carry out their responsibilities related to operations and supply chain security within the context of organizational information security programs. [SP 800-181] provides guidance on role-based information security training in the workplace. [SP 800-161] provides guidance on supply chain risk management.

Potential indicators and possible precursors of insider threat include behaviors such as: inordinate, long-term job dissatisfaction; attempts to gain access to information that is not required for job performance; unexplained access to financial resources; bullying or sexual harassment of fellow employees; workplace violence; and other serious violations of the policies, procedures, directives, rules, or practices of organizations. Security awareness training includes how to communicate employee and management concerns regarding potential indicators of insider threat through appropriate organizational channels in accordance with established organizational policies and procedures. Organizations may consider tailoring insider threat awareness topics to the role (e.g., training for managers may be focused on specific changes in behavior of team members, while training for employees may be focused on more general observations).

An event is any observable occurrence in a system, which includes unlawful or unauthorized system activity. Organizations identify event types for which a logging functionality is needed as those events which are significant and relevant to the security of systems and the environments in which those systems operate to meet specific and ongoing auditing needs. Event types can include password changes, failed logons or failed accesses related to systems, administrative privilege usage, or third-party credential usage. In determining event types that require logging, organizations consider the monitoring and auditing appropriate for each of the CUI security requirements. Monitoring and auditing requirements can be balanced with other system needs. For example, organizations may determine that systems must have the capability to log every file access both successful and unsuccessful, but not activate that capability except for specific circumstances due to the potential burden on system performance. Audit records can be generated at various levels of abstraction, including at the packet level as information traverses the network. Selecting the appropriate level of abstraction is a critical aspect of an audit logging capability and can facilitate the identification of root causes to problems. Organizations consider in the definition of event types, the logging necessary to cover related events such as the steps in distributed, transaction-based processes (e.g., processes that are distributed across multiple organizations) and actions that occur in service-oriented or cloud-based architectures. Audit record content that may be necessary to satisfy this requirement includes time stamps, source and destination addresses, user or process identifiers, event descriptions, success or fail indications, filenames involved, and access control or flow control rules invoked. Event outcomes can include indicators of event success or failure and event-specific results (e.g., the security state of the system after the event occurred). Detailed information that organizations may consider in audit records includes full text recording of privileged commands or the individual identities of group account users. Organizations consider limiting the additional audit log information to only that information explicitly needed for specific audit requirements. This facilitates the use of audit trails and audit logs by not including information that could potentially be misleading or could make it more difficult to locate information of interest. Audit logs are reviewed and analyzed as often as needed to provide important information to organizations to facilitate risk-based decision making. [SP 800-92] provides guidance on security log management.

This requirement ensures that the contents of the audit record include the information needed to link the audit event to the actions of an individual to the extent feasible. Organizations consider logging for traceability including results from monitoring of account usage, remote access, wireless connectivity, mobile device connection, communications at system boundaries, configuration settings, physical access, nonlocal maintenance, use of maintenance tools, temperature and humidity, equipment delivery and removal, system component inventory, use of mobile code, and use of Voice over Internet Protocol (VoIP).

The intent of this requirement is to periodically re-evaluate which logged events will continue to be included in the list of events to be logged. The event types that are logged by organizations may change over time. Reviewing and updating the set of logged event types periodically is necessary to ensure that the current set remains necessary and sufficient.

Audit logging process failures include software and hardware errors, failures in the audit record capturing mechanisms, and audit record storage capacity being reached or exceeded. This requirement applies to each audit record data storage repository (i.e., distinct system component where audit records are stored), the total audit record storage capacity of organizations (i.e., all audit record data storage repositories combined), or both.

Correlating audit record review, analysis, and reporting processes helps to ensure that they do not operate independently, but rather collectively. Regarding the assessment of a given organizational system, the requirement is agnostic as to whether this correlation is applied at the system level or at the organization level across all systems.