CVE-2025-34256
Advantech WISE-DeviceOn Server < 5.4 Hard-coded JWT Key Authentication Bypass
- State
- Published
- Severity
- 10.0 Critical
- Published
- Dec 5, 2025
- Updated
- Aug 14, 2026
- Reserved
- Apr 15, 2025
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 10.0 Critical | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H | VulnCheck |
Weaknesses
- CWE-321 Use of Hard-coded Cryptographic Key
Affected Products
| Product | Versions |
|---|---|
WISE-DeviceOn ServerAdvantech Co., Ltd. |
|
References
- https://advcloudfiles.advantech.com/cms/2ca1b071-fd78-4d7f-8a2a-7b4537a95d19/Security%20Advisory%20PDF%20File/SECURITY-ADVISORY----DeviceOn-20251208-2.pdfvendor-advisorypatch
- https://pellera.com/blog/advantech-wise-deviceon-cve-2025-34256-vulnerability/technical-descriptionexploit
- https://docs.deviceon.advantech.com/docs/resource/product
- https://www.vulncheck.com/advisories/advantech-wise-deviceon-server-hardcoded-jwt-key-authentication-bypassthird-party-advisory
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