PE 11 Emergency Power

---
name: "PE-11_emergency-power"
description: "Provide an uninterruptible power supply to facilitate [organization-defined] in the event of a primary power source loss."
category: "configuration"
version: "5.2.0"
author: "cyberstrike-official"
tags:
  - nist
  - sp800-53
  - rev5
  - pe-11
  - pe
tech_stack:
  - any
cwe_ids: []
chains_with:
  - AT-3
  - CP-2
  - CP-7
prerequisites: []
severity_boost:
  AT-3: "Chain with AT-3 for comprehensive security coverage"
  CP-2: "Chain with CP-2 for comprehensive security coverage"
  CP-7: "Chain with CP-7 for comprehensive security coverage"
---

# PE-11 Emergency Power

## High-Level Description

**Family:** Physical and Environmental Protection (PE)
**Framework:** NIST SP 800-53 Rev 5

An uninterruptible power supply (UPS) is an electrical system or mechanism that provides emergency power when there is a failure of the main power source. A UPS is typically used to protect computers, data centers, telecommunication equipment, or other electrical equipment where an unexpected power disruption could cause injuries, fatalities, serious mission or business disruption, or loss of data or information. A UPS differs from an emergency power system or backup generator in that the UPS provides near-instantaneous protection from unanticipated power interruptions from the main power source by providing energy stored in batteries, supercapacitors, or flywheels. The battery duration of a UPS is relatively short but provides sufficient time to start a standby power source, such as a backup generator, or properly shut down the system.

## What to Check

- [ ] Verify PE-11 Emergency Power is documented in SSP
- [ ] Confirm control is operating effectively
- [ ] Review evidence of continuous monitoring for PE-11

## How to Test

### Step 1: Review Documentation

Examine the System Security Plan (SSP) and related artifacts for PE-11 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

Provide an uninterruptible power supply to facilitate [organization-defined] in the event of a primary power source loss.

### Implementation Guidance

An uninterruptible power supply (UPS) is an electrical system or mechanism that provides emergency power when there is a failure of the main power source. A UPS is typically used to protect computers, data centers, telecommunication equipment, or other electrical equipment where an unexpected power disruption could cause injuries, fatalities, serious mission or business disruption, or loss of data or information. A UPS differs from an emergency power system or backup generator in that the UPS provides near-instantaneous protection from unanticipated power interruptions from the main power source by providing energy stored in batteries, supercapacitors, or flywheels. The battery duration of a UPS is relatively short but provides sufficient time to start a standby power source, such as a backup generator, or properly shut down the system.

## Risk Assessment

| Finding                               | Severity | Impact                                           |
| ------------------------------------- | -------- | ------------------------------------------------ |
| PE-11 Emergency Power not implemented | Medium   | Physical and Environmental Protection            |
| PE-11 partially implemented           | Low      | Incomplete Physical and Environmental Protection |

## CWE Categories

| CWE ID | Title                 |
| ------ | --------------------- |
| N/A    | No direct CWE mapping |

## References

- [NIST SP 800-53 Rev 5 - PE-11](https://csrc.nist.gov/projects/cprt/catalog#/cprt/framework/version/SP_800_53_5_1_1/home?element=pe-11)
- [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 (AT-3, CP-2, CP-7) reviewed