Control statement
For [Organization-defined: system components] , load and execute:
- a.The operating environment from hardware-enforced, read-only media; and
- b.The following applications from hardware-enforced, read-only media: [Organization-defined: applications].
Discussion
The operating environment for a system contains the code that hosts applications, including operating systems, executives, or virtual machine monitors (i.e., hypervisors). It can also include certain applications that run directly on hardware platforms. Hardware-enforced, read-only media include Compact Disc-Recordable (CD-R) and Digital Versatile Disc-Recordable (DVD-R) disk drives as well as one-time, programmable, read-only memory. The use of non-modifiable storage ensures the integrity of software from the point of creation of the read-only image. The use of reprogrammable, read-only memory can be accepted as read-only media provided that integrity can be adequately protected from the point of initial writing to the insertion of the memory into the system, and there are reliable hardware protections against reprogramming the memory while installed in organizational systems.
Organization-defined parameters
These values must be resolved through the organization’s tailoring and governance process. Bracketed parameter references in the control text identify where a decision is required.
From control text to operational evidence
Use Non-modifiable Executable Programs as a testable risk decision. Translate the official statement into accountable people, repeatable processes, configured technology, and evidence that demonstrates the outcome over time. In this family, pay particular attention to secure architecture, boundary protection, communications protection, cryptography, and system isolation.
Implementation workflow
- Define the control boundary, responsible owner, inherited portions, and systems or processes in scope.
- Resolve each organization-defined parameter before declaring the control implemented.
- Document how the implementation satisfies every clause of the official control statement.
- Collect evidence as a normal byproduct of operation rather than only before an assessment.
- Review exceptions, changes, and monitoring results on a risk-based cadence.
Evidence examples
- network and trust-boundary diagrams
- firewall and gateway configurations
- cryptographic configuration and key records
- segmentation and isolation test results
Common failure patterns
- diagrams omit cloud and third-party paths
- encryption enabled without key governance
- flat trust zones allow unnecessary lateral movement
- boundary rules accumulate without owner review
Questions practitioners should ask
- What risk decision is this control intended to support in this system?
- Which parts are implemented locally, inherited, shared, or not applicable—and what evidence supports that decision?
- Do the documented narrative, deployed configuration, operating process, and collected evidence agree?
- What event or threshold requires the implementation to be reviewed or changed?
Assessment objectives and methods
Show the assessment objective
- SC-34a.the operating environment for [Organization-defined: system components] is loaded and executed from hardware-enforced, read-only media;
- SC-34b.[Organization-defined: applications] for [Organization-defined: system components] are loaded and executed from hardware-enforced, read-only media.
Examine
- System and communications protection policy
- procedures addressing non-modifiable executable programs
- system design documentation
- system configuration settings and associated documentation
- system architecture
- list of operating system components to be loaded from hardware-enforced, read-only media
- list of applications to be loaded from hardware-enforced, read-only media
- media used to load and execute the system operating environment
- media used to load and execute system applications
- system audit records
- system security plan
- other relevant documents or records
Interview
- System/network administrators
- organizational personnel with information security responsibilities
- system developer
- organizational personnel installing, configuring, and/or maintaining the system
- system developers/integrators
Test
- Mechanisms supporting and/or implementing, loading, and executing the operating environment from hardware-enforced, read-only media
- mechanisms supporting and/or implementing, loading, and executing applications from hardware-enforced, read-only media
Related controls
These relationships come from the official OSCAL catalog. They indicate useful dependencies or context, not automatic inheritance or equivalence.
Control enhancements
Enhancements add specificity, strength, or scope to the base control. Baseline badges show explicit selections in the official SP 800-53B OSCAL profiles.
SC-34(1) — No Writable Storage
Employ [Organization-defined: system components] with no writeable storage that is persistent across component restart or power on/off.
Official discussion
Disallowing writeable storage eliminates the possibility of malicious code insertion via persistent, writeable storage within the designated system components. The restriction applies to fixed and removable storage, with the latter being addressed either directly or as specific restrictions imposed through access controls for mobile devices.
Organization-defined parameters (1)
Assessment objectives and methods
[Organization-defined: system components] are employed with no writeable storage that is persistent across component restart or power on/off.
Examine
- System and communications protection policy
- procedures addressing non-modifiable executable programs
- system design documentation
- system configuration settings and associated documentation
- system architecture
- list of system components to be employed without writeable storage capabilities
- system audit records
- system security plan
- other relevant documents or records
Interview
- System/network administrators
- organizational personnel with information security responsibilities
- organizational personnel installing, configuring, and/or maintaining the system
- system developers/integrators
Test
- Mechanisms supporting and/or implementing the employment of components with no writeable storage
- mechanisms supporting and/or implementing persistent non-writeable storage across component restart and power on/off
Related controls
SC-34(2) — Integrity Protection on Read-only Media
Protect the integrity of information prior to storage on read-only media and control the media after such information has been recorded onto the media.
Official discussion
Controls prevent the substitution of media into systems or the reprogramming of programmable read-only media prior to installation into the systems. Integrity protection controls include a combination of prevention, detection, and response.
Assessment objectives and methods
- SC-34(02)[01]the integrity of information is protected prior to storage on read-only media;
- SC-34(02)[02]the media is controlled after such information has been recorded onto the media;
Examine
- System and communications protection policy
- procedures addressing non-modifiable executable programs
- system design documentation
- system configuration settings and associated documentation
- system architecture
- system audit records
- system security plan
- other relevant documents or records
Interview
- System/network administrators
- organizational personnel with information security responsibilities
- organizational personnel installing, configuring, and/or maintaining the system
- system developers/integrators
Test
- Mechanisms supporting and/or implementing the capability to protect information integrity on read-only media prior to storage and after information has been recorded onto the media
Related controls
SC-34(3) — Hardware-based Protection
This enhancement is marked withdrawn in the official OSCAL catalog. Related-control metadata below may identify where its intent was incorporated.
Authoritative sources
Bare Metal Cyber is an independent educational publisher and is not affiliated with or endorsed by NIST. Official control requirements and interpretations remain with NIST and the responsible authorizing organization.