Sensitive Information Uncleared Before Debug/Power State Transition

The product performs a power or debug state transition, but it does not clear sensitive information that should no longer be accessible due to changes to information access restrictions.

Abstraction

Base

Structure

Simple

Likelihood of Exploit

Medium

Understand the problem

What is the problem?

The product performs a power or debug state transition, but it does not clear sensitive information that should no longer be accessible due to changes to information access restrictions.

Extended description

A device or system frequently employs many power and sleep states during its normal operation (e.g., normal power, additional power, low power, hibernate, deep sleep, etc.). A device also may be operating within a debug condition. State transitions can happen from one power or debug state to another. If there is information available in the previous state which should not be available in the next state and is not properly removed before the transition into the next state, sensitive information may leak from the system.

Root cause

How and when does the problem arise?

Lifecycle phase

Architecture and Design

Risk

What does successful exploitation lead to?

Read MemoryRead Application Data

Affected security scopes: Confidentiality, Integrity, Availability, Access Control, Accountability, Authentication, Authorization, Non-Repudiation

Sensitive information may be used to unlock additional capabilities of the device and take advantage of hidden functionalities which could be used to compromise device security.

Defence

How is it prevented and fixed?

Architecture and Design · Implementation

Defence to apply across several lifecycle phases

Detail

During state transitions, information not needed in the next state should be removed before the transition to the next state.

Verification

How is it detected?

Manual Analysis

High

Write a known pattern into each sensitive location. Enter the power/debug state in question. Read data back from the sensitive locations. If the reads are successful, and the data is the same as the pattern that was originally written, the test fails and the device needs to be fixed. Note that this test can likely be automated.