CWE-1231 Detail

The product uses a trusted lock bit for restricting access to registers, address regions, or other resources, but the product does not prevent the value of the lock bit from being modified after it has been set.

In integrated circuits and hardware intellectual property (IP) cores, device configuration controls are commonly programmed after a device power reset by a trusted firmware or software module (e.g., BIOS/bootloader) and then locked from any further modification.

This behavior is commonly implemented using a trusted lock bit. When set, the lock bit disables writes to a protected set of registers or address regions. Design or coding errors in the implementation of the lock bit protection feature may allow the lock bit to be modified or cleared by software after it has been set. Attackers might be able to unlock the system and features that the bit is intended to protect.

Modes Of Introduction

Architecture and Design : Such issues could be introduced during hardware architecture and design and identified later during Testing or System Configuration phases.
Implementation : Such issues could be introduced during implementation and identified later during Testing or System Configuration phases.

Applicable Platforms

Language

Class: Not Language-Specific (Undetermined)

Operating Systems

Class: Not OS-Specific (Undetermined)

Architectures

Class: Not Architecture-Specific (Undetermined)

Technologies

Class: Not Technology-Specific (Undetermined)

Common Consequences

Observed Examples

Potential Mitigations

Phases : Architecture and Design // Implementation // Testing

• Security lock bit protections must be reviewed for design inconsistency and common weaknesses.
• Security lock programming flow and lock properties must be tested in pre-silicon and post-silicon testing.

Detection Methods

Manual Analysis

Set the lock bit. Power cycle the device. Attempt to clear the lock bit. If the information is changed, implement a design fix. Retest. Also, attempt to indirectly clear the lock bit or bypass it.
Effectiveness : High

Vulnerability Mapping Notes

Justification : This CWE entry is at the Base level of abstraction, which is a preferred level of abstraction for mapping to the root causes of vulnerabilities.
Comment : Carefully read both the name and description to ensure that this mapping is an appropriate fit. Do not try to 'force' a mapping to a lower-level Base/Variant simply to comply with this preferred level of abstraction.

Related Attack Patterns

References

REF-1350

reglk_wrapper.sv
https://github.com/HACK-EVENT/hackatdac21/blob/b9ecdf6068445d76d6bee692d163fededf7a9d9b/piton/design/chip/tile/ariane/src/reglk/reglk_wrapper.sv#L80C1-L80C48

REF-1351

fix cwe 1199 in reglk
https://github.com/HACK-EVENT/hackatdac21/commit/5928add42895b57341ae8fc1f9b8351c35aed865#diff-1c2b09dd092a56e5fb2be431a3849e72ff489d2ae4f4a6bb9c0ea6b7d450135aR80

Submission

Modifications