What evidence do auditors commonly ask for on SC-39 Process Isolation?

System design documentation; System architecture; Independent verification and validation documentation; Testing and evaluation documentation; Test of Mechanisms supporting and/or implementing separate execution domains for each executing process.

What is the most common gap auditors find on SC-39?

Executing system processes share address space, with no separate execution domain maintained for each

NIST SP 800-53 Rev 5 · SC - System and Communications Protection

`SC-39` Process Isolation

Maintain a separate execution domain for each executing system process.

Source: NIST SP 800-53 Rev 5, SC-39. The statement above is our statement of the clause, read from the published text and cited so you can check it against the official text, not the instrument verbatim. Open NIST SP 800-53 Rev 5 in the compliance library.

Base controls and their enhancements. Which apply follows the baseline you are assessed against (for example FedRAMP Moderate or High, or the low, moderate and high baselines of SP 800-53B). Text in square brackets is a parameter your organisation sets.

artefacts

held by a system

at each review

hard

to go live

Document repository

where the evidence lives

teal = a system already holds it · olive = produced at each review. To go live: easy when half or more of the artefacts are already held by a system, moderate from a quarter to a half, hard below a quarter.

These are the artefacts auditors commonly ask for on this requirement, our guidance rather than text from the standard. Your assessor decides what is sufficient in your context, and asks for samples across the period when a report covers one.

system holds itEvidence a system already holds

none for this control

periodic reviewEvidence produced at each review

Test of Mechanisms supporting and/or implementing separate execution domains for each executing process · Document repository

governing documentDocuments that govern the control

System design documentation · Document repository
System architecture · Policy repository / GRC workspace
Independent verification and validation documentation · Document repository
Testing and evaluation documentation · Document repository

First move

No system holds this evidence for you: it is people and documents. Reminders and routing to the owner still save time. Put the document under version control with an owner and review date, and log each review as a record with reviewer and date.

Common gaps auditors find

Executing system processes share address space, with no separate execution domain maintained for each
Operating system process isolation features are disabled or not configured on the system components

Do this for your whole sheet

Paste the rows you run your controls from and get this mapping for every control at once, with the periodic-review ones flagged and a first move per row. No account for the first run.

Build my evidence sheet

SC-38 Operations Security · SC-39(1) Process Isolation | Hardware Separation