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Withdrawn on May 14, 2024. Superseded by SP 800-171 Rev. 3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
AC-3.4.8 Apply deny-by-exception (blacklisting) policy to prevent the use of unauthorized software or deny-all, permit-by-exception (whitelisting) policy to allow the execution of authorized software.
Control Family: Configuration Management
Control Type: Derived
SPRS Value: 5
SPRS Supplemental Guidance:
N/A
CMMC Level(s):
CM.L2-3.4.8
Top Ten Failed Requirement:
No
Referenced in:
DFARS 252.204-7012
Derived From: NIST SP 800-53r4
CM-7(4)
CM-7(5)
NIST Supplemental Guidance:
[SP 800-167]
Discussion:
The process used to identify software programs that are not authorized to execute on systems is commonly referred to as blacklisting. The process used to identify software programs that are authorized to execute on systems is commonly referred to as whitelisting. Whitelisting is the stronger of the two policies for restricting software program execution. In addition to whitelisting, organizations consider verifying the integrity of whitelisted software programs using, for example, cryptographic checksums, digital signatures, or hash functions. Verification of whitelisted software can occur either prior to execution or at system startup.
[SP 800-167] provides guidance on application whitelisting.
Upon assessment, assessors must determine if-
3.4.8[a] a policy specifying whether whitelisting or blacklisting is to be implemented is
specified.
3.4.8[b] the software allowed to execute under whitelisting or denied use under
blacklisting is specified.
3.4.8[c] whitelisting to allow the execution of authorized software or blacklisting to
prevent the use of unauthorized software is implemented as specified.
defined.
3.4.7[m] essential services are defined.
3.4.7[n] the use of nonessential services is defined.
3.4.7[o] the use of nonessential services is restricted, disabled, or prevented as defined.
Assessors are instructed to-
Examine: [SELECT FROM: Configuration management policy; procedures addressing least functionality in the system; system security plan; configuration management plan; system design documentation; system configuration settings and associated documentation; list of software programs not authorized to execute on the system; list of software programs authorized to execute on the system; security configuration checklists; review and update records associated with list of authorized or unauthorized software programs; change control records; system audit logs and records; other relevant documents or records].
Interview: [SELECT FROM: Personnel with responsibilities for identifying software authorized or not authorized to execute on the system; personnel with information security responsibilities; system or network administrators].
Test: [SELECT FROM: Organizational process for identifying, reviewing, and updating programs authorized or not authorized to execute on the system; process for implementing blacklisting or whitelisting; mechanisms supporting or implementing blacklisting or whitelisting].