CWE - CWE-1189: Improper Isolation of Shared Resources on System-on-a-Chip (SoC) (4.20)

Weakness ID: 1189

Vulnerability Mapping: ALLOWED This CWE ID may be used to map to real-world vulnerabilities
Abstraction: Base Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.

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Description

The System-On-a-Chip (SoC) does not properly isolate shared resources between trusted and untrusted agents.

Extended Description

A System-On-a-Chip (SoC) has a lot of functionality, but it may have a limited number of pins or pads. A pin can only perform one function at a time. However, it can be configured to perform multiple different functions. This technique is called pin multiplexing. Similarly, several resources on the chip may be shared to multiplex and support different features or functions. When such resources are shared between trusted and untrusted agents, untrusted agents may be able to access the assets intended to be accessed only by the trusted agents.

Common Consequences

This table 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.

Impact	Details
Bypass Protection Mechanism	Scope: Access Control If resources being used by a trusted user are shared with an untrusted user, the untrusted user may be able to modify the functionality of the shared resource of the trusted user.
Quality Degradation	Scope: Integrity The functionality of the shared resource may be intentionally degraded.

Potential Mitigations

Phase(s)	Mitigation
Architecture and Design	Strategy: Separation of Privilege When sharing resources, avoid mixing agents of varying trust levels. Untrusted agents should not share resources with trusted agents.

Relationships

This table 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" (View-1000)

Nature	Type	ID	Name
ChildOf	Class - 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.	653	Improper Isolation or Compartmentalization
ChildOf	Class - 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.	668	Exposure of Resource to Wrong Sphere
ParentOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	1303	Non-Transparent Sharing of Microarchitectural Resources
PeerOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	1331	Improper Isolation of Shared Resources in Network On Chip (NoC)

Relevant to the view "Hardware Design" (View-1194)

Nature	Type	ID	Name
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1198	Privilege Separation and Access Control Issues
PeerOf	Base - a weakness that is still mostly independent of a resource or technology, but with sufficient details to provide specific methods for detection and prevention. Base level weaknesses typically describe issues in terms of 2 or 3 of the following dimensions: behavior, property, technology, language, and resource.	1331	Improper Isolation of Shared Resources in Network On Chip (NoC)

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.

Phase	Note
Architecture and Design
Implementation

Applicable Platforms

This listing shows 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: Not Language-Specific (Undetermined Prevalence)
Technologies	Class: System on Chip (Undetermined Prevalence)

Demonstrative Examples

Example 1

Consider the following SoC design. The Hardware Root of Trust (HRoT) local SRAM is memory mapped in the core{0-N} address space. The HRoT allows or disallows access to private memory ranges, thus allowing the sram to function as a mailbox for communication between untrusted and trusted HRoT partitions.

We assume that the threat is from malicious software in the untrusted domain. We assume this software has access to the core{0-N} memory map and can be running at any privilege level on the untrusted cores. The capability of this threat in this example is communication to and from the mailbox region of SRAM modulated by the hrot_iface. To address this threat, information must not enter or exit the shared region of SRAM through hrot_iface when in secure or privileged mode.

Selected Observed Examples

Note: this is a curated list of examples for users to understand the variety of ways in which this weakness can be introduced. It is not a complete list of all CVEs that are related to this CWE entry.

Reference	Description
CVE-2020-8698	Processor has improper isolation of shared resources allowing for information disclosure.
CVE-2019-6260	Baseboard Management Controller (BMC) device implements Advanced High-performance Bus (AHB) bridges that do not require authentication for arbitrary read and write access to the BMC's physical address space from the host, and possibly the network [REF-1138].

Weakness Ordinalities

Ordinality	Description
Primary	(where the weakness exists independent of other weaknesses)

Detection Methods

Method	Details
Automated Dynamic Analysis	Pre-silicon / post-silicon: Test access to shared systems resources (memory ranges, control registers, etc.) from untrusted software to verify that the assets are not incorrectly exposed to untrusted agents. Note that access to shared resources can be dynamically allowed or revoked based on system flows. Security testing should cover such dynamic shared resource allocation and access control modification flows. Effectiveness: High

Method

Details

Automated Dynamic Analysis

Pre-silicon / post-silicon: Test access to shared systems resources (memory ranges, control registers, etc.) from untrusted software to verify that the assets are not incorrectly exposed to untrusted agents. Note that access to shared resources can be dynamically allowed or revoked based on system flows. Security testing should cover such dynamic shared resource allocation and access control modification flows.

Effectiveness: High

Memberships

This MemberOf Relationships table shows additional CWE Categories and Views that reference this weakness as a member. This information is often useful in understanding where a weakness fits within the context of external information sources.

Nature	Type	ID	Name
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	1343	Weaknesses in the 2021 CWE Most Important Hardware Weaknesses List
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1364	ICS Communications: Zone Boundary Failures
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1366	ICS Communications: Frail Security in Protocols
MemberOf	Category - a CWE entry that contains a set of other entries that share a common characteristic.	1418	Comprehensive Categorization: Violation of Secure Design Principles
MemberOf	View - a subset of CWE entries that provides a way of examining CWE content. The two main view structures are Slices (flat lists) and Graphs (containing relationships between entries).	1432	Weaknesses in the 2025 CWE Most Important Hardware Weaknesses List

Vulnerability Mapping Notes

Usage	ALLOWED (this CWE ID may be used to map to real-world vulnerabilities)
Reason	Acceptable-Use
Rationale	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.
Comments	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

CAPEC-ID	Attack Pattern Name
CAPEC-124	Shared Resource Manipulation

References

[REF-1036]	Ali Abbasi and Majid Hashemi. "Ghost in the PLC Designing an Undetectable Programmable Logic Controller Rootkit via Pin Control Attack". 2016. <https://www.blackhat.com/docs/eu-16/materials/eu-16-Abbasi-Ghost-In-The-PLC-Designing-An-Undetectable-Programmable-Logic-Controller-Rootkit-wp.pdf>.
[REF-1138]	Stewart Smith. "CVE-2019-6260: Gaining control of BMC from the host processor". 2019. <https://www.flamingspork.com/blog/2019/01/23/cve-2019-6260:-gaining-control-of-bmc-from-the-host-processor/>. (URL validated: 2025-07-29)

Content History

Submissions
Submission Date	Submitter	Organization
2019-10-15 (CWE 4.0, 2020-02-24)	Arun Kanuparthi, Hareesh Khattri, Parbati Kumar Manna, Narasimha Kumar V Mangipudi	Intel Corporation
2019-10-15 (CWE 4.0, 2020-02-24)
Contributions
Contribution Date	Contributor	Organization
2022-04-18	Hareesh Khattri	Intel Corporation
2022-04-18	changed detection method
2021-10-22	Hareesh Khattri	Intel Corporation
2021-10-22	provided observed example
2021-07-16		Cycuity (originally submitted as Tortuga Logic)
2021-07-16	Provided Demonstrative Example for Hardware Root of Trust.
Modifications
Modification Date	Modifier	Organization
2025-09-09 (CWE 4.18, 2025-09-09)	CWE Content Team	MITRE
2025-09-09 (CWE 4.18, 2025-09-09)	updated Relationships
2025-04-03 (CWE 4.17, 2025-04-03)	CWE Content Team	MITRE
2025-04-03 (CWE 4.17, 2025-04-03)	updated Demonstrative_Examples
2023-06-29 (CWE 4.12, 2023-06-29)	CWE Content Team	MITRE
2023-06-29 (CWE 4.12, 2023-06-29)	updated Mapping_Notes, Relationships
2023-04-27 (CWE 4.11, 2023-04-27)	CWE Content Team	MITRE
2023-04-27 (CWE 4.11, 2023-04-27)	updated Observed_Examples, Relationships
2022-10-13 (CWE 4.9, 2022-10-13)	CWE Content Team	MITRE
2022-10-13 (CWE 4.9, 2022-10-13)	updated Detection_Factors
2021-10-28 (CWE 4.6, 2021-10-28)	CWE Content Team	MITRE
2021-10-28 (CWE 4.6, 2021-10-28)	updated Description, Observed_Examples, References, Relationships, Weakness_Ordinalities
2021-07-20 (CWE 4.5, 2021-07-20)	CWE Content Team	MITRE
2021-07-20 (CWE 4.5, 2021-07-20)	updated Demonstrative_Examples
2020-12-10 (CWE 4.3, 2020-12-10)	CWE Content Team	MITRE
2020-12-10 (CWE 4.3, 2020-12-10)	updated Relationships
2020-08-20 (CWE 4.2, 2020-08-20)	CWE Content Team	MITRE
2020-08-20 (CWE 4.2, 2020-08-20)	updated Common_Consequences, Description, Name, Potential_Mitigations, Related_Attack_Patterns, Relationships
Previous Entry Names
Change Date	Previous Entry Name
2020-08-20	Improper Isolation of Shared Resources on System-on-Chip (SoC)

CWE Glossary Definition


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Common Weakness Enumeration

CWE-1189: Improper Isolation of Shared Resources on System-on-a-Chip (SoC)

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