CVE-2025-34256

CRITICAL

Advantech WISE-DeviceOn Server <5.4 - Auth Bypass

Title source: llm

Description

Advantech WISE-DeviceOn Server versions prior to 5.4 contain a hard-coded cryptographic key vulnerability. The product uses a static HS512 HMAC secret for signing EIRMMToken JWTs across all installations. The server accepts forged JWTs that need only contain a valid email claim, allowing a remote unauthenticated attacker to generate arbitrary tokens and impersonate any DeviceOn account, including the root super admin. Successful exploitation permits full administrative control of the DeviceOn instance and can be leveraged to execute code on managed agents through DeviceOn’s remote management features.

References (3)

[Various Sources] https://advcloudfiles.advantech.com/cms/2ca1b071-fd78-4d7f-8a2a-7b4537a95d19/Security%20Advisory%20PDF%20File/SECURITY-ADVISORY----DeviceOn-20251208-2.pdf

[Product] https://docs.deviceon.advantech.com/docs/resource/

[Third Party Advisory] https://www.vulncheck.com/advisories/advantech-wise-deviceon-server-hardcoded-jwt-key-authentication-bypass

Scores

CVSS v3 9.8

EPSS 0.0025

EPSS Percentile 47.6%

Attack Vector NETWORK

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Classification

CWE

CWE-321

Status published

Affected Products (1)

advantech/wise-deviceon_server < 5.4

Timeline

Published Dec 05, 2025

Tracked Since Feb 18, 2026