Trouble at the top: can Python extend the chains of trust in infrastructure firmware?

arXiv:2609.27802 · cs.CR · Submitted 2026-08-17 · Read on arXiv

cs.CR

Submitted: 2026-08-17

Updated: 2026-08-17

Comments: Work in progress. Presented at the 2026 Symposium on the Science of Security (HotSoS 2026), Session 2, April 14, 2026. Session listing: https://sos-vo.org/group/hotsos/2026/hernandez 9 pages, 2 figures, 4 tables

Code: https://github.com/brettcannon/presentations

License: http://creativecommons.org/licenses/by-nc-nd/4.0/

The gist: Compiled Python bytecode (PYC) has become an essential part of network switches, routers, and other network infrastructure devices.

Terminology

Abstract

Compiled Python bytecode (PYC) has become an essential part of network switches, routers, and other network infrastructure devices. Our analysis shows that its integrity is implicitly trusted in multiple designs that make use of Python code at the top of the operational software, such as the management and control pane of enterprise network switches. At the same time, the integrity of PYC files is not covered under the traditional chain-of-trust models, due to complex interactions with the CPython loader, byte compiler, and other Python runtime components. We explore the risks inherent in including PYC and Python runtimes in the de facto trusted code basis of commercial enterprise equipment and offer a comprehensive framework for understanding emergent behaviors in these designs.

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