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Withdrawn on May 14, 2024. Superseded by SP 800-171 Rev. 3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
3.1.6 Use non-privileged accounts or roles when accessing nonsecurity functions.
Control Family: Access Control
Control Type: Derived
SPRS Value: 1
CMMC Level(s): AC.L2-3.1.6
Top Ten Failed Requirement: No
Referenced in:
DFARS 252.204-7012
Derived From: NIST SP 800-53r4
AC-6(2)
Discussion:
This requirement limits exposure when operating from within privileged accounts or roles. The inclusion of roles addresses situations where organizations implement access control policies such as role-based access control and where a change of role provides the same degree of assurance in the change of access authorizations for the user and all processes acting on behalf of the user as would be provided by a change between a privileged and non-privileged account.
Determining Statements (NIST SP 800-171Ar2)
Upon assessment, assessors must determine if-
3.1.6[a] nonsecurity functions are identified.
3.1.6[b] users are required to use non-privileged accounts or roles when accessing
nonsecurity functions.
Assessors are instructed to-
Examine: [SELECT FROM: Access control policy; procedures addressing least privilege; system security plan; list of system-generated security functions assigned to system accounts or roles; system configuration settings and associated documentation; system audit logs and records; other relevant documents or records].
Interview: [SELECT FROM: Personnel with responsibilities for defining least privileges necessary to accomplish specified organizational tasks; personnel with information security responsibilities; system or network administrators].
Test: [SELECT FROM: Mechanisms implementing least privilege functions].
FURTHER DISCUSSION
A user with a privileged account can perform more tasks and access more information than a person with a non-privileged account. Tasks (including unauthorized tasks orchestrated by attackers) performed when using the privileged account can have a greater impact on the system. System administrators and users with privileged accounts must be trained not to use their privileged accounts for everyday tasks, such as browsing the internet or connecting unnecessarily to other systems or services.
Example
You are logged in using your privileged account and you need to look up how to reset a nonfunctioning application which processes CUI. You should log on to another computer with your non-privileged account before you connect to the web and start searching for the reset information [b]. That way, if your account is compromised during the search, it will be your regular user account rather than an account with elevated privileges.
Potential Assessment Considerations
Are nonsecurity functions and non-privileged roles defined [a,b]?
Is it required that nonsecurity functions only be accessed with the use of non-privileged accounts? How is this verified [b]?
Frameworks & Controls
3.1.3: Control the flow of CUI in accordance with approved authorizations
3.1.6: Use non-privileged accounts or roles when accessing nonsecurity functions
3.1.9: Provide privacy and security notices consistent with applicable CUI rules
3.1.11: Terminate (automatically) a user session after a defined condition
3.1.13: Employ cryptographic mechanisms to protect the confidentiality of remote access sessions
3.1.14: Route remote access via managed access control points
3.1.16: Authorize wireless access prior to allowing such connections
3.1.17: Protect wireless access using authentication and encryption
3.1.19: Encrypt CUI on mobile devices and mobile computing platforms
3.1.20: Verify and control/limit connections to and use of external systems
3.1.21: Limit use of portable storage devices on external systems
3.1.22: Control CUI posted or processed on publicly accessible systems