NIST Special Publication 800-171 Revision 2

Date Published: January 28th, 2021

Withdrawn on May 14, 2024. Superseded by SP 800-171 Rev. 3

Author(s): Ron Ross (NIST), Victoria Pillitteri (NIST), Kelley Dempsey (NIST), Mark Riddle (NARA), Gary Guissanie (IDA)

Note: A Class Deviation is in effect as of May 2, 2024 (DEVIATION 2024O0013). The deviation clause requires contractors, who are subject to 252.204-7012, to comply with National Institute of Standards and Technology (NIST) Special Publication (SP) 800-171 Revision 2, instead of the version of NIST SP 800-171 in effect at the time the solicitation is issued or as authorized by the contracting officer. Click Here

3.1.22 Control CUI posted or processed on publicly accessible systems.

Control Family: Access Control

Control Type: Derived

SPRS Value: 1

SPRS Supplemental Guidance:

N/A

CMMC Level(s): AC.L2-3.1.14

Top Ten Failed Requirement: No

Referenced in:

DFARS 252.204-7012

Derived From: NIST SP 800-53r4

  • AC-22

NIST Supplemental Guidance:

N/A

Discussion:

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.

Upon assessment, assessors must determine if-

3.1.22[a] individuals authorized to post or process information on publicly accessible
systems are identified.
3.1.22[b] procedures to ensure CUI is not posted or processed on publicly accessible
systems are identified.
3.1.22[c] a review process is in place prior to posting of any content to publicly
accessible systems.
3.1.22[d] content on publicly accessible systems is reviewed to ensure that it does not
include CUI.
3.1.22[e] mechanisms are in place to remove and address improper posting of CUI.

Assessors are instructed to-

Examine: [SELECT FROM: Access control policy; procedures addressing publicly accessible content; system security plan; list of users authorized to post publicly accessible content on organizational systems; training materials and/or records; records of publicly accessible information reviews; records of response to nonpublic information on public websites; system audit logs and records; security awareness training records; other relevant documents or records].

Interview: [SELECT FROM: Personnel with responsibilities for managing publicly accessible information posted on organizational systems; personnel with information security responsibilities].

Test: [SELECT FROM: Mechanisms implementing management of publicly accessible content].

FURTHER DISCUSSION

Only government officials can be authorized to release CUI to the public. Do not allow CUI to become public – always safeguard the confidentiality of CUI by controlling the posting of CUI on company-controlled websites or public forums, and the exposure of CUI in public presentations or on public displays. It is important to know which users are allowed to publish information on publicly accessible systems, like your company website, and implement a review process before posting such information. If CUI is discovered on a publicly accessible system, procedures should be in place to remove that information and alert the appropriate parties.

Example

Your company decides to start issuing press releases about its projects in an effort to reach more potential customers. Your company receives CUI from the government as part of its DoD contract. Because you recognize the need to manage controlled information, including CUI, you meet with the employees who write the releases and post information to establish a review process [c]. It is decided that you will review press releases for CUI before posting it on the company website [a,d]. Only certain employees will be authorized to post to the website [a].

Potential Assessment Considerations

  • Does information on externally facing systems (i.e., publicly accessible) have a documented approval chain for public release [c]?

Frameworks & Controls