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CVE-2025-34256

Advantech WISE-DeviceOn Server < 5.4 Hard-coded JWT Key Authentication Bypass

Published: Dec 5, 2025Updated: Apr 15, 2026 Sources: CVE List NVDCWE-321
NVD MITRE
9.8CVSSCRITICAL
EPSS Score
0.6%
Top 56.3%
CISA KEV
Not in KEV
Exploits
No Known Exploits
Remediation
No Fix Available

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.

CVSS Vector Breakdown

AV:NAC:LPR:NUI:NS:UC:HI:HA:H
Exploitability
AV:NAttack Vector
Network
AC:LAttack Complexity
Low
PR:NPrivileges Required
None
UI:NUser Interaction
None
Scope
S:UScope
Unchanged
Impact
C:HConfidentiality
High
I:HIntegrity
High
A:HAvailability
High
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Weaknesses

CWE-321

Affected Products

wise-deviceon serveradvantechICS / OT / IoT
WISE-DeviceOn ServerAdvantech Co., Ltd.
On-prem
ICS / OT / IoT / industrial-network
advantechcommercialTWICS / OT / IoTaka webaccess, advantech webaccess, r-seenet
advantech co., ltd.commercialICS / OT / IoTaka wise-deviceon server

Exploitability

No known exploits, KEV entries, or remediation guidance available for this vulnerability yet.

References

https://advcloudfiles.advantech.com/cms/2ca1b071-fd78-4d7f-8a2a-7b4537a95d19/Security%20Advisory%20PDF%20File/SECURITY-ADVISORY----DeviceOn-20251208-2.pdf
advcloudfiles.advantech.com
https://docs.deviceon.advantech.com/docs/resource/
docs.deviceon.advantech.com
https://pellera.com/blog/advantech-wise-deviceon-cve-2025-34256-vulnerability/
pellera.com
and 1 more references View all →

Timeline

Published
Dec 5, 2025
Last Updated
Apr 15, 2026

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