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ID

CWE-1232: Improper Lock Behavior After Power State Transition

Weakness ID: 1232
Abstraction: Base
Structure: Simple
Status: Incomplete
Presentation Filter:
+ Description
The product implements register lock bit protection features with the intent to disable changes to system configuration after the lock is set. Some of the protected registers or lock bits become programmable after power state transitions (e.g., Entry and wake from low power sleep modes).
+ Extended Description

Integrated circuits and hardware IPs can expose the device configuration controls that need to be programmed after device power reset by a trusted firmware or software module (commonly set by BIOS/bootloader) and then locked from any further modification. In hardware design this is commonly implemented using a programmable lock bit, which when set disables writes to a protected set of registers or address regions.

Some common weaknesses that can exist in such a protection scheme is that the lock gets cleared, the values of the protected registers get reset, or the lock become programmable after a power state transition.

+ Relationships

The table(s) below shows the weaknesses and high level categories that are related to this weakness. These relationships are defined as ChildOf, ParentOf, MemberOf and give insight to similar items that may exist at higher and lower levels of abstraction. In addition, relationships such as PeerOf and CanAlsoBe are defined to show similar weaknesses that the user may want to explore.

+ Relevant to the view "Research Concepts" (CWE-1000)
NatureTypeIDName
ChildOfClassClass - a weakness that is described in a very abstract fashion, typically independent of any specific language or technology. More specific than a Pillar Weakness, but more general than a Base Weakness. Class level weaknesses typically describe issues in terms of 1 or 2 of the following dimensions: behavior, property, and resource.667Improper Locking
+ Relevant to the view "Hardware Design" (CWE-1194)
NatureTypeIDName
MemberOfCategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic.1199General Circuit and Logic Design Concerns
MemberOfCategoryCategory - a CWE entry that contains a set of other entries that share a common characteristic.1206Power, Clock, and Reset Concerns
+ Modes Of Introduction

The different Modes of Introduction provide information about how and when this weakness may be introduced. The Phase identifies a point in the life cycle at which introduction may occur, while the Note provides a typical scenario related to introduction during the given phase.

PhaseNote
Architecture and DesignSuch issues could be introduced during hardware architecture and design or implementation and identified later during Testing or System Configuration phases.
ImplementationSuch issues could be introduced during hardware architecture and design or implementation and identified later during Testing or System Configuration phases.
+ Applicable Platforms
The listings below show possible areas for which the given weakness could appear. These may be for specific named Languages, Operating Systems, Architectures, Paradigms, Technologies, or a class of such platforms. The platform is listed along with how frequently the given weakness appears for that instance.

Languages

Class: Language-Independent (Undetermined Prevalence)

Operating Systems

Class: OS-Independent (Undetermined Prevalence)

Architectures

Class: Architecture-Independent (Undetermined Prevalence)

Technologies

Class: Technology-Independent (Undetermined Prevalence)

+ Common Consequences

The table below specifies different individual consequences associated with the weakness. The Scope identifies the application security area that is violated, while the Impact describes the negative technical impact that arises if an adversary succeeds in exploiting this weakness. The Likelihood provides information about how likely the specific consequence is expected to be seen relative to the other consequences in the list. For example, there may be high likelihood that a weakness will be exploited to achieve a certain impact, but a low likelihood that it will be exploited to achieve a different impact.

ScopeImpactLikelihood
Access Control

Technical Impact: Modify Memory

System Configuration protected by lock bit can be modified even when lock is set.
High
+ Demonstrative Examples

Example 1

Consider memory configuration settings of a system that uses DDR3 DRAM memory. Protecting the DRAM memory configuration from modification by software is required to ensure that system memory access control protections cannot be bypassed. This can be done by using a lock bit protection that locks all memory configuration registers. The memory configuration lock can be set by BIOS on boot.

If such a system also supports a low power sleep state like hibernate, the DRAM data must be saved in disk and restored when system resumes from hibernate. During hibernate, system DRAM would be powered off.

To support hibernate power transition flow, the DRAM memory configuration must be reprogrammed even though it was locked previously. During hibernate resume, the memory configuration could be modified or memory lock cleared.

Functionally the hibernate resume flow requires a bypass of the lock-based protection.

The memory configuration must be securely stored and restored by trusted system firmware. Lock settings and system configuration must be restored to same state as before entry to hibernate mode.

+ Potential Mitigations

Phases: Architecture and Design; Implementation; Testing

  • Security Lock bit protections must be reviewed for behavior across supported power state transitions.
  • Security lock programming flow and lock properties must be tested in pre-si, post-si testing, including testing these across power transitions.

Effectiveness: High

+ Content History
+ Submissions
Submission DateSubmitterOrganization
2020-01-15Arun Kanuparthi, Hareesh Khattri, Parbati Kumar Manna, Narasimha Kumar V MangipudiIntel Corporation
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Page Last Updated: June 25, 2020