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Base weakness

Incomplete

CWE-1276: Hardware Child Block Incorrectly Connected to Parent System

Signals between a hardware IP and the parent system design are incorrectly connected causing security risks.

Last updated May 1, 2026

0

Recorded CVEs

With this primary weakness

0

KEVs

In the CISA KEV catalog

Not rated

Likelihood of exploit

Per MITRE

Base

Abstraction

MITRE classification

Overview

Individual hardware IP must communicate with the parent system in order for the product to function correctly and as intended. If implemented incorrectly, while not causing any apparent functional issues, may cause security issues. For example, if the IP should only be reset by a system-wide hard reset, but instead the reset input is connected to a software-triggered debug mode reset (which is also asserted during a hard reset), integrity of data inside the IP can be violated.

Common consequences

What can happen when CWE-1276 is exploited.

Varies by Context

Affects: Confidentiality, Integrity, Availability

How it happens

When it is introduced

Typically introduced during these phases of the software lifecycle.

Implementation

How to prevent it

Practical mitigations for CWE-1276, grouped by where in the lifecycle they apply.

Testing

System-level verification may be used to ensure that components are correctly connected and that design security requirements are not violated due to interactions between various IP blocks.

Code examples

Illustrative examples from MITRE showing how the weakness appears in code.

Many SoCs use hardware to partition system resources between trusted and untrusted entities. One example of this concept is the Arm TrustZone, in which the processor and all security-aware IP attempt to isolate resources based on the status of a privilege bit. This privilege bit is part of the input interface in all TrustZone-aware IP. If this privilege bit is accidentally grounded or left unconnected when the IP is instantiated, privilege escalation of all input data may occur.

In the Verilog code below, the security level input to the TrustZone aware peripheral is correctly driven by an appropriate signal instead of being grounded.

Here is a code snippet from the Ariane core module in the HACK@DAC'21 Openpiton SoC [REF-1362]. To ensure full functional correctness, developers connect the ports with names. However, in some cases developers forget to connect some of these ports to the desired signals in the parent module. These mistakes by developers can lead to incorrect functional behavior or, in some cases, introduce security vulnerabilities.

Frequently asked questions

Common questions about CWE-1276.

What is CWE-1276?

Signals between a hardware IP and the parent system design are incorrectly connected causing security risks.

How do you prevent CWE-1276?

System-level verification may be used to ensure that components are correctly connected and that design security requirements are not violated due to interactions between various IP blocks.

What are the consequences of CWE-1276?

Exploiting CWE-1276 can lead to: Varies by Context.

References

Weakness data is sourced from the MITRE CWE catalog (v4.20). CVE associations are aggregated and kept current by RadicalNotion.AI.

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Code examples

Overview

Common consequences

How it happens

When it is introduced

How to prevent it

Code examples

Related weaknesses

Parent

Frequently asked questions

What is CWE-1276?

How do you prevent CWE-1276?

What are the consequences of CWE-1276?

References

Stay ahead of CWE-1276