Another Crack in the Chain of Trust: Uncovering (Yet Another) Secure Boot Bypass

Original Article ↗ Hacker News Discussion ↗

Secure Boot, “User Infantilization,” and Owner Control

  • Some see Secure Boot as a paternalistic “trust us” mechanism: factories ship machines trusting Microsoft- or vendor-signed blobs, not the owner’s choices.
  • Others argue they like being able to restrict a machine to known-good binaries and see value in signing, especially for large fleets.

Signatures vs Hashes and Remote Attestation

  • One camp claims signatures add nothing beyond what a simple owner-configured hash of the bootloader would provide for local integrity; they argue certificates exist mainly to enable remote attestation, viewed as dangerous.
  • Counterpoint: in large deployments, a CA-based model simplifies updates versus manually updating hashes on thousands of machines.

TPM, Keys, and Threat Models

  • Debate over TPMs: some insist factory keys are inherently bad because they enable third parties to compel attestation; others clarify TPM factory keys are separate from Secure Boot keys and firmware uses only public keys.
  • Disagreement on whether persistence via bootloader replacement matters if the attacker already has root; critics say at that point you’re effectively compromised anyway, defenders note bootkits and long‑term stealth are distinct risks.

Firmware Quality and Industry Economics

  • The specific bug (unsafe NVRAM handling, even serializing raw pointers) is cited as emblematic of sloppy firmware engineering.
  • Explanations offered: security competes with cost and time-to-market; firmware is not a selling point; “lemon market” dynamics push out high-quality vendors.
  • Hardware companies are said to undervalue software talent and often ship third‑party firmware (IBVs) with limited source and support, making secure designs rare.

UEFI vs BIOS and Alternative Designs

  • Some nostalgically prefer BIOS, claiming UEFI just enlarges the attack surface; others note BIOS wasn’t secure either and could not realistically match modern Secure Boot capabilities.
  • Alternatives discussed: TPM+Heads, coreboot with verified boot, removable read-only boot media (e.g., SD card with a write switch) as a simple owner-controlled root of trust.

Enterprise, DRM, and Anti‑Cheat

  • Many argue Secure Boot primarily serves enterprises (locked-down corporate fleets) and is being repurposed for consumer control (Windows 11 requirements, anti‑cheat systems, potential DRM).
  • Concern: software that requires Secure Boot can coerce users into accepting specific trust anchors, limiting practical software freedom.