Control the use of removable media on system components
📖 What This Means
This practice requires organizations to limit and monitor the use of removable media (like USB drives, external hard drives, or CDs) on systems that handle Controlled Unclassified Information (CUI). It means you need to have policies and technical controls in place to prevent unauthorized copying or transfer of CUI via these devices. For example, you might disable USB ports on workstations or require encryption for all removable media. A real-world example would be a defense contractor that only allows pre-approved encrypted USB drives for transferring CUI between secure systems, with each use logged. Another example is disabling DVD burners on engineering workstations that handle sensitive design files.
🎯 Why It Matters
Uncontrolled removable media poses significant data exfiltration risks. The 2020 DoD Cyber Exchange reported that 15% of data breaches involved removable media. A well-known case is the 2008 Pentagon breach where malware spread via USB drives, costing $500M+ in remediation. For defense contractors, a single unencrypted USB with CUI could lead to contract termination, fines up to $1M, and loss of security clearance eligibility. The DoD specifically calls out removable media controls in DFARS 252.204-7012 as a critical safeguard against insider threats and accidental data loss.
✅ How to Implement
- 1. Configure Azure Conditional Access or AWS IAM policies to block cloud data transfers to removable media
- 2. Implement Microsoft Defender for Endpoint or AWS Macie to detect and alert on unauthorized media use
- 3. Deploy Intune or Workspace ONE to enforce device control policies on cloud-managed endpoints
- 4. Use Azure Information Protection or AWS Key Management Service to enforce encryption requirements
- 5. Enable logging in CloudTrail/Azure Monitor for media-related events
📋 Evidence Examples
Removable Media Policy
Group Policy Settings Screenshot
Media Usage Logs
Encrypted Media Inventory
Employee Training Records
📝 SSP Guidance
Use this guidance when writing the System Security Plan (SSP) narrative for this control.
How to Write the SSP Narrative
For MP.L2-3.8.7 ("Control the use of removable media on system components"), your SSP narrative should specifically describe: (1) the tools and technologies you use to implement this control, (2) the configuration or process that enforces it, (3) who is responsible for maintaining it, and (4) what evidence proves it's working. Describe how CUI on media is protected throughout its lifecycle, including encryption, access controls, marking, transport procedures, sanitization methods, and accountability tracking. Be specific -- name your actual products, settings, and responsible personnel.
Example SSP Narratives
"MP.L2-3.8.7 is implemented using cloud-native controls. [Organization] uses [specific cloud service/feature] to control the use of removable media on system components. The configuration is managed through [Azure Policy/AWS Config/Terraform] and monitored via [SIEM tool]. Responsible party: [IT Security Manager]. Evidence: [specific artifact, e.g., 'Azure AD Conditional Access policy screenshot, CloudTrail logs']."
"MP.L2-3.8.7 is implemented through on-premise infrastructure controls. [Organization] uses [Active Directory/Group Policy/specific tool] to control the use of removable media on system components. Configuration is documented in [location] and audited [frequency]. Responsible party: [System Administrator]. Evidence: [specific artifact, e.g., 'Group Policy export, Windows Event logs']."
"MP.L2-3.8.7 is implemented across both cloud and on-premise environments. [Organization] uses [Azure AD Connect/hybrid tool] to ensure consistent enforcement. Cloud resources are managed via [cloud tool] and on-premise systems via [on-prem tool]. Both environments report to [centralized SIEM]. Responsible party: [IT Director]. Evidence: [artifacts from both environments]."
System Boundary Considerations
- • Identify all removable media types within the CUI boundary
- • Document media storage locations (on-site, off-site)
- • Specify media sanitization and destruction methods
- • Ensure this control covers all systems within your defined CUI boundary where control the use of removable media on system components applies
- • Document any systems where this control is not applicable and explain why
Key Documentation to Reference in SSP
- 📄 Media Protection Policy
- 📄 Media inventory database
- 📄 Certificates of destruction
- 📄 Transport chain-of-custody records
- 📄 Evidence artifacts specific to MP.L2-3.8.7
- 📄 POA&M entry if control is not fully implemented
What the Assessor Looks For
The assessor will check for CUI markings on media, verify encryption is enabled, review the media inventory for completeness, and examine destruction certificates.
💬 Self-Assessment Questions
Use these questions to assess your compliance. Each "NO" answer provides specific remediation guidance.
Question 1: Do you have a written policy governing removable media use with CUI?
Question 2: Are technical controls in place to block unauthorized removable media?
Question 3: Is all approved removable media encrypted?
Question 4: Are media insertion events logged and reviewed?
Question 5: Do employees receive annual training on media policies?
⚠️ Common Mistakes (What Auditors Flag)
1. Allowing personal USB drives without oversight
2. Missing logs of media usage
3. Inconsistent enforcement across devices
4. No process for media sanitization
5. Failing to test controls
📚 Parent Policy
This practice is governed by the Media Protection Policy