Protocol-Aware Firmware Rehosting for Effective Fuzzing of Embedded Network Stacks

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Bley, Moritz, Scharnowski, Tobias, Wörner, Simon, Schloegel, Moritz, Holz, Thorsten
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866911158982672384
author Bley, Moritz
Scharnowski, Tobias
Wörner, Simon
Schloegel, Moritz
Holz, Thorsten
author_facet Bley, Moritz
Scharnowski, Tobias
Wörner, Simon
Schloegel, Moritz
Holz, Thorsten
contents One of the biggest attack surfaces of embedded systems is their network interfaces, which enable communication with other devices. Unlike their general-purpose counterparts, embedded systems are designed for specialized use cases, resulting in unique and diverse communication stacks. Unfortunately, current approaches for evaluating the security of these embedded network stacks require manual effort or access to hardware, and they generally focus only on small parts of the embedded system. A promising alternative is firmware rehosting, which enables fuzz testing of the entire firmware by generically emulating the physical hardware. However, existing rehosting methods often struggle to meaningfully explore network stacks due to their complex, multi-layered input formats. This limits their ability to uncover deeply nested software faults. To address this problem, we introduce a novel method to automatically detect and handle the use of network protocols in firmware called Pemu. By automatically deducing the available network protocols, Pemu can transparently generate valid network packets that encapsulate fuzzing data, allowing the fuzzing input to flow directly into deeper layers of the firmware logic. Our approach thus enables a deeper, more targeted, and layer-by-layer analysis of firmware components that were previously difficult or impossible to test. Our evaluation demonstrates that Pemu consistently improves the code coverage of three existing rehosting tools for embedded network stacks. Furthermore, our fuzzer rediscovered several known vulnerabilities and identified five previously unknown software faults, highlighting its effectiveness in uncovering deeply nested bugs in network-exposed code.
format Preprint
id arxiv_https___arxiv_org_abs_2509_13740
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Protocol-Aware Firmware Rehosting for Effective Fuzzing of Embedded Network Stacks
Bley, Moritz
Scharnowski, Tobias
Wörner, Simon
Schloegel, Moritz
Holz, Thorsten
Cryptography and Security
One of the biggest attack surfaces of embedded systems is their network interfaces, which enable communication with other devices. Unlike their general-purpose counterparts, embedded systems are designed for specialized use cases, resulting in unique and diverse communication stacks. Unfortunately, current approaches for evaluating the security of these embedded network stacks require manual effort or access to hardware, and they generally focus only on small parts of the embedded system. A promising alternative is firmware rehosting, which enables fuzz testing of the entire firmware by generically emulating the physical hardware. However, existing rehosting methods often struggle to meaningfully explore network stacks due to their complex, multi-layered input formats. This limits their ability to uncover deeply nested software faults. To address this problem, we introduce a novel method to automatically detect and handle the use of network protocols in firmware called Pemu. By automatically deducing the available network protocols, Pemu can transparently generate valid network packets that encapsulate fuzzing data, allowing the fuzzing input to flow directly into deeper layers of the firmware logic. Our approach thus enables a deeper, more targeted, and layer-by-layer analysis of firmware components that were previously difficult or impossible to test. Our evaluation demonstrates that Pemu consistently improves the code coverage of three existing rehosting tools for embedded network stacks. Furthermore, our fuzzer rediscovered several known vulnerabilities and identified five previously unknown software faults, highlighting its effectiveness in uncovering deeply nested bugs in network-exposed code.
title Protocol-Aware Firmware Rehosting for Effective Fuzzing of Embedded Network Stacks
topic Cryptography and Security
url https://arxiv.org/abs/2509.13740