Improper Isolation of Shared Resources in Network On Chip (NoC)

The Network On Chip (NoC) does not isolate or incorrectly isolates its on-chip-fabric and internal resources such that they are shared between trusted and untrusted agents, creating timing channels.

Abstraction

Base

Structure

Simple

Likelihood of Exploit

Medium

Understand the problem

What is the problem?

The Network On Chip (NoC) does not isolate or incorrectly isolates its on-chip-fabric and internal resources such that they are shared between trusted and untrusted agents, creating timing channels.

Extended description

Typically, network on chips (NoC) have many internal resources that are shared between packets from different trust domains. These resources include internal buffers, crossbars and switches, individual ports, and channels. The sharing of resources causes contention and introduces interference between differently trusted domains, which poses a security threat via a timing channel, allowing attackers to infer data that belongs to a trusted agent. This may also result in introducing network interference, resulting in degraded throughput and latency.

Root cause

How and when does the problem arise?

Lifecycle phase

Architecture and Design

Lifecycle phase

Implementation

"Network-on-chip" (NoC) is a commonly-used term used for hardware interconnect fabrics used by multicore Systems-on-Chip (SoC). Communication between modules on the chip uses packet-based methods, with improved efficiency and scalability compared to bus architectures [REF-1241].

Risk

What does successful exploitation lead to?

DoS: Resource Consumption (Other)Varies by ContextOther

Affected security scopes: Confidentiality, Availability

Attackers may infer data that belongs to a trusted agent. The methods used to perform this attack may result in noticeably increased resource consumption.

Defence

How is it prevented and fixed?

Architecture and Design · Implementation

Defence to apply across several lifecycle phases

Detail

Implement priority-based arbitration inside the NoC and have dedicated buffers or virtual channels for routing secret data from trusted agents.

Verification

How is it detected?

Manual Analysis

Moderate

Providing marker flags to send through the interfaces coupled with examination of which users are able to read or manipulate the flags will help verify that the proper isolation has been achieved and is effective.