Description
The increase in connectivity of embedded systems has led to a significant growth of
their attack surface. The combination of microcontrollers lacking robust hardware
protections and the reliance on complex, memory-unsafe network stacks in embedded
systems is particularly concerning.
This thesis addresses this concern. Based on the CHERIoT architecture, we propose
two architectures to restrict the blast radius of a potential exploit in an embedded
system with a CANopen protocol stack. In both architectures, software components
are compartmentalized and CAN frames filtered. The first architecture provides a
lightweight firewall designed for reusing legacy C/C++ CAN stacks. The second
architecture also features a firewall, but additionally offers strict flow isolation via
sockets.
We implement these architectures on a CHERIoT evaluation board. The resilience of
the system is demonstrated through fault injection, showing safe recovery of crashed
components without compromising the entire system. Its real-time viability is assessed
by measuring latency and compartmentalization overhead.
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Thesis topic in co-operation with the Fraunhofer Institute for Applied and Integrated Security AISEC, Garching