CVE-2025-34256: Advantech WISE-DeviceOn Server · Use of Hard-coded Cryptographic Key
Affects Advantech WISE-DeviceOn ServerSource CVE Database V5
Not known to be exploited · CVSS 10.0 Critical : upgrade to 5.4 as a priority.
Data as of 26 Oct 2026, 14:05 UTC
- EPSS
- 0.6% chance of exploitation in 30 days – higher than 52% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 5.4
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:HExploitation evidence
Disclosed: evidence found.
CVE published 5 Dec 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
What to do
Upgrade Advantech WISE-DeviceOn Server to 5.4.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| Advantech Co., Ltd. WISE-DeviceOn Server | Affected
| Fixed in
|
AI-suggested
If you cannot patch yet, restrict access to the DeviceOn server and monitor for suspicious JWT tokens. Avoid exposing the server to untrusted networks.
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
- advcloudfiles.advantech.com/cms/2ca1b071-fd78-4d7f-8a2a-7b4537a95d19/Security%20Advisory%20PDF%20File/SECURITY-ADVISORY----DeviceOn-20251208-2.pdf (opens in a new tab)
- pellera.com/blog/advantech-wise-deviceon-cve-2025-34256-vulnerability/ (opens in a new tab)
- docs.deviceon.advantech.com/docs/resource/ (opens in a new tab)
- vulncheck.com/advisories/advantech-wise-deviceon-server-hardcoded-jwt-key-authentication-bypass (opens in a new tab)