Description
The Ingenic T31 SoC boot ROM flash-boot verification path compares only a single 32-bit word of the RSA signature output against a single 32-bit word of the SHA-256 payload digest, rather than compare the full data. This allows an attacker with physical write access to boot media to forge modified SPL (Secondary Program Loader) images that pass secure boot verification without possession of the OEM signing key. Each forgery attempt succeeds with approximately 2/3 probability. This has been validated via reverse engineering, software emulation against vendor-signed images, and end-to-end hardware acceptance of a forged firmware image on a Wyze Video Doorbell v2 (T31X).
Published: 2026-08-19
Score: 6.4 Medium
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

Impact

The Ingenic T31 SoC boot ROM contains a cryptographic validation flaw: it compares only a single 32‑bit word of the RSA signature with a single 32‑bit word of the SHA‑256 payload digest instead of verifying the full data. Consequently, an attacker who can write to the boot media can create a forged Secondary Program Loader (SPL) image that passes the incomplete check. Each forged image succeeds with an estimated probability of about two‑thirds, allowing repeated attempts until a signed image is accepted. This flaw permits an attacker to run arbitrary firmware on a device that thinks it is operating with genuine, vendor‑signed code.

Affected Systems

Devices that use the Ingenic T31 System‑on‑Chip, such as the Wyze Video Doorbell v2 (T31X), are affected. The vulnerability resides in the boot ROM’s flash‑boot verification path and applies to any equipment that relies on this chip for secure boot. No explicit software product versions or vendor patches are listed in the CNA data; the problem is intrinsic to the hardware firmware.

Risk and Exploitability

The EPSS score of <1% and the fact that the vulnerability is not listed in the CISA KEV catalog indicate that public reports of exploitation are currently limited. The CVSS score of 6.4 indicates a moderate severity. An attacker who gains physical access can replace the critical early boot code, potentially installing malware, gaining persistent control, or disabling device functionality. The impact is severe, affecting confidentiality, integrity, and availability of the entire system. The limited availability of information about any vendor fix or mitigation suggests the risk is high until a confirmed patch is applied.

Generated by OpenCVE AI on August 24, 2026 at 23:21 UTC.

Remediation

No vendor fix or workaround currently provided.

OpenCVE Recommended Actions

  • Apply the latest vendor firmware or boot ROM that corrects the cryptographic verification logic (if released).
  • Physically secure the boot media and device enclosure to prevent tampering or unauthorized writes.
  • Verify the integrity of existing firmware by comparing stored hashes and signatures against trusted values and roll back to a known clean image if discrepancies are found.

Generated by OpenCVE AI on August 24, 2026 at 23:21 UTC.

Tracking

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Advisories

No advisories yet.

History

Mon, 24 Aug 2026 23:45:00 +0000

Type Values Removed Values Added
Title Ingenic T31 Boot ROM Secure-Boot Verification Flaw Allows Firmware Forgery

Mon, 24 Aug 2026 22:15:00 +0000

Type Values Removed Values Added
Title Partial RSA Signature Verification in Ingenic T31 Secure Boot Allows Forgery
Weaknesses CWE-20
CWE-330

Mon, 24 Aug 2026 20:30:00 +0000

Type Values Removed Values Added
Weaknesses CWE-347
Metrics cvssV3_1

{'score': 6.4, 'vector': 'CVSS:3.1/AV:P/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H'}

ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Fri, 21 Aug 2026 21:45:00 +0000

Type Values Removed Values Added
First Time appeared Opensensor
Opensensor ingenic T31
Vendors & Products Opensensor
Opensensor ingenic T31

Thu, 20 Aug 2026 07:45:00 +0000

Type Values Removed Values Added
Title Partial RSA Signature Verification in Ingenic T31 Secure Boot Allows Forgery
Weaknesses CWE-20
CWE-330

Thu, 20 Aug 2026 04:30:00 +0000

Type Values Removed Values Added
Title Ingenic T31 Boot ROM Allows Forged Secure Boot Images with 67% Success Rate
Weaknesses CWE-307

Wed, 19 Aug 2026 19:15:00 +0000

Type Values Removed Values Added
Title Ingenic T31 Boot ROM Allows Forged Secure Boot Images with 67% Success Rate
Weaknesses CWE-307

Wed, 19 Aug 2026 14:00:00 +0000

Type Values Removed Values Added
Description The Ingenic T31 SoC boot ROM flash-boot verification path compares only a single 32-bit word of the RSA signature output against a single 32-bit word of the SHA-256 payload digest, rather than compare the full data. This allows an attacker with physical write access to boot media to forge modified SPL (Secondary Program Loader) images that pass secure boot verification without possession of the OEM signing key. Each forgery attempt succeeds with approximately 2/3 probability. This has been validated via reverse engineering, software emulation against vendor-signed images, and end-to-end hardware acceptance of a forged firmware image on a Wyze Video Doorbell v2 (T31X).
References

Subscriptions

Opensensor Ingenic T31
cve-icon MITRE

Status: PUBLISHED

Assigner: mitre

Published:

Updated: 2026-08-24T19:59:08.374Z

Reserved: 2026-06-05T00:00:00.000Z

Link: CVE-2026-50720

cve-icon Vulnrichment

Updated: 2026-08-24T19:58:37.823Z

cve-icon NVD

Status : Deferred

Published: 2026-08-19T14:17:32.130

Modified: 2026-09-09T16:04:24.933

Link: CVE-2026-50720

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-08-24T23:30:17Z

Weaknesses
  • CWE-347

    Improper Verification of Cryptographic Signature