Weakness · High
CWE-1189: Improper Isolation of Shared Resources on System-on-a-Chip (SoC)
What it is
The System-On-a-Chip (SoC) does not properly isolate shared resources between trusted and untrusted agents.
- Severity (our rating)
- High
- Likelihood of exploit
- Not rated by MITRE
- Introduced during
- Architecture and Design, Implementation
- Exploited in the wild
- No CVE in CISA's catalog
In more detail
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.
What an attacker can do
- Bypass Protection Mechanism (Access Control)
- Quality Degradation (Integrity)
How to prevent it
Architecture and Design
- When sharing resources, avoid mixing agents of varying trust levels. Untrusted agents should not share resources with trusted agents.
How to find it
- 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.
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Start freeSource: MITRE Common Weakness Enumeration, CWE version 4.19.1. CWE is a trademark of The MITRE Corporation.