CWE-1274 Detail

The product conducts a secure-boot process that transfers bootloader code from Non-Volatile Memory (NVM) into Volatile Memory (VM), but it does not have sufficient access control or other protections for the Volatile Memory.

Adversaries could bypass the secure-boot process and execute their own untrusted, malicious boot code.

As a part of a secure-boot process, the read-only-memory (ROM) code for a System-on-Chip (SoC) or other system fetches bootloader code from Non-Volatile Memory (NVM) and stores the code in Volatile Memory (VM), such as dynamic, random-access memory (DRAM) or static, random-access memory (SRAM). The NVM is usually external to the SoC, while the VM is internal to the SoC. As the code is transferred from NVM to VM, it is authenticated by the SoC's ROM code.

If the volatile-memory-region protections or access controls are insufficient to prevent modifications from an adversary or untrusted agent, the secure boot may be bypassed or replaced with the execution of an adversary's code.

Modes Of Introduction

Architecture and Design : This weakness can be introduced during hardware architecture or design but can be identified later during testing.

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
Ensure that the design of volatile-memory protections is enough to prevent modification from an adversary or untrusted code.
Phases : Testing
Test the volatile-memory protections to ensure they are safe from modification or untrusted code.

Detection Methods

Manual Analysis

Ensure the volatile memory is lockable or has locks. Ensure the volatile memory is locked for writes from untrusted agents or adversaries. Try modifying the volatile memory from an untrusted agent, and ensure these writes are dropped.
Effectiveness : High

Manual Analysis

Analyze the device using the following steps:

1. Identify all fabric master agents that are active during system Boot Flow when initial code is loaded from Non-volatile storage to volatile memory.
2. Identify the volatile memory regions that are used for storing loaded system executable program.
3. During system boot, test programming the identified memory regions in step 2 from all the masters identified in step 1.

Only trusted masters should be allowed to write to the memory regions. For example, pluggable device peripherals should not have write access to program load memory regions.

Effectiveness : Moderate

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

Submission

Modifications