SA 8(6) Minimized Sharing

---
name: "SA-8(6)_minimized-sharing"
description: "Implement the security design principle of minimized sharing in [organization-defined]."
category: "configuration"
version: "5.2.0"
author: "cyberstrike-official"
tags:
  - nist
  - sp800-53
  - rev5
  - sa-8-6
  - sa
  - enhancement
tech_stack:
  - any
cwe_ids:
  - CWE-16
chains_with:
  - SC-31
prerequisites:
  - SA-8
severity_boost:
  SC-31: "Chain with SC-31 for comprehensive security coverage"
---

# SA-8(6) Minimized Sharing

> **Enhancement of:** SA-8

## High-Level Description

**Family:** System and Services Acquisition (SA)
**Framework:** NIST SP 800-53 Rev 5

The principle of minimized sharing states that no computer resource is shared between system components (e.g., subjects, processes, functions) unless it is absolutely necessary to do so. Minimized sharing helps to simplify system design and implementation. In order to protect user-domain resources from arbitrary active entities, no resource is shared unless that sharing has been explicitly requested and granted. The need for resource sharing can be motivated by the design principle of least common mechanism in the case of internal entities or driven by stakeholder requirements. However, internal sharing is carefully designed to avoid performance and covert storage and timing channel problems. Sharing via common mechanism can increase the susceptibility of data and information to unauthorized access, disclosure, use, or modification and can adversely affect the inherent capability provided by the system. To minimize sharing induced by common mechanisms, such mechanisms can be designed to be reentrant or virtualized to preserve separation. Moreover, the use of global data to share information is carefully scrutinized. The lack of encapsulation may obfuscate relationships among the sharing entities.

## What to Check

- [ ] Verify SA-8(6) Minimized Sharing is documented in SSP
- [ ] Confirm control is operating effectively
- [ ] Review evidence of continuous monitoring for SA-8(6)
- [ ] Verify enhancement builds upon base control SA-8

## How to Test

### Step 1: Review Documentation

Examine the System Security Plan (SSP) and related artifacts for SA-8(6) implementation details. Verify the organization has documented how this control is satisfied.

### Step 2: Validate Implementation

```
# For cloud environments, use cloud-audit-mcp tools
# For on-premises, review system configurations directly

# Example: Check if account management policies exist
grep -r "account.management\|access.control" /etc/security/ 2>/dev/null
```

### Step 3: Test Operating Effectiveness

Verify the control is actively functioning, not just documented. Check logs, configurations, and operational evidence.

## Tools

| Tool          | Purpose                           | Usage |
| ------------- | --------------------------------- | ----- |
| Manual Review | Documentation and interview-based | N/A   |

## Remediation Guide

### Control Statement

Implement the security design principle of minimized sharing in [organization-defined].

### Implementation Guidance

The principle of minimized sharing states that no computer resource is shared between system components (e.g., subjects, processes, functions) unless it is absolutely necessary to do so. Minimized sharing helps to simplify system design and implementation. In order to protect user-domain resources from arbitrary active entities, no resource is shared unless that sharing has been explicitly requested and granted. The need for resource sharing can be motivated by the design principle of least common mechanism in the case of internal entities or driven by stakeholder requirements. However, internal sharing is carefully designed to avoid performance and covert storage and timing channel problems. Sharing via common mechanism can increase the susceptibility of data and information to unauthorized access, disclosure, use, or modification and can adversely affect the inherent capability provided by the system. To minimize sharing induced by common mechanisms, such mechanisms can be designed to be reentrant or virtualized to preserve separation. Moreover, the use of global data to share information is carefully scrutinized. The lack of encapsulation may obfuscate relationships among the sharing entities.

## Risk Assessment

| Finding                                   | Severity | Impact                                     |
| ----------------------------------------- | -------- | ------------------------------------------ |
| SA-8(6) Minimized Sharing not implemented | Medium   | System and Services Acquisition            |
| SA-8(6) partially implemented             | Low      | Incomplete System and Services Acquisition |

## CWE Categories

| CWE ID | Title         |
| ------ | ------------- |
| CWE-16 | Configuration |

## References

- [NIST SP 800-53 Rev 5 - SA-8(6)](https://csrc.nist.gov/projects/cprt/catalog#/cprt/framework/version/SP_800_53_5_1_1/home?element=sa-8.6)
- [NIST SP 800-53A Rev 5 (Assessment Procedures)](https://csrc.nist.gov/pubs/sp/800/53/a/r5/final)
- [NIST SP 800-53 Rev 5 Full Catalog](https://csrc.nist.gov/pubs/sp/800/53/r5/upd1/final)

## Checklist

- [ ] Control documented in SSP
- [ ] Implementation evidence collected
- [ ] Operating effectiveness validated
- [ ] Continuous monitoring in place
- [ ] Related controls (SC-31) reviewed