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

Opis

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

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.

Skutki

• Access Control

  Bypass Protection Mechanism

  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.

• Integrity

  Quality Degradation

  The functionality of the shared resource may be intentionally degraded.

Zapobieganie

• Architecture and Design · Separation of Privilege

  When sharing resources, avoid mixing agents of varying trust levels.

  Untrusted agents should not share resources with trusted agents.

Przykłady podatności

• 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].

Słabość nadrzędna

• CWE-653 Improper Isolation or Compartmentalization
• CWE-668 Exposure of Resource to Wrong Sphere

Pokrewna

• CWE-1331 Improper Isolation of Shared Resources in Network On Chip (NoC)

Słabości podrzędne

• CWE-1303 Non-Transparent Sharing of Microarchitectural Resources

Kiedy powstaje

• Architecture and Design
• Implementation

Dotyczy

Not Language-Specific, System on Chip

Źródła

1. Ghost in the PLC Designing an Undetectable Programmable Logic Controller Rootkit via Pin Control Attack — Ali Abbasi and Majid Hashemi, 2016
2. CVE-2019-6260: Gaining control of BMC from the host processor — Stewart Smith, 2019