Vulnerability in Advantech Wise-Deviceon Server
CVE-2025-34256
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 0.007 (50.9th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 51st percentile — 50.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.007 · newest: 0.007 · change: -0.000
Affected products
Weakness classification (CWE)
References
- advcloudfiles.advantech.com/cms/2ca1b071-fd78-4d7f-8a2a-7b4537a95d19/Security A… (vendor-advisory, patch)
- pellera.com/blog/advantech-wise-deviceon-cve-2025-34256-vulnerability/ (technical-description, exploit)
- docs.deviceon.advantech.com/docs/resource/ (Product, product)
- www.vulncheck.com/advisories/advantech-wise-deviceon-server-hardcoded-jwt-key-a… (Third Party Advisory, third-party-advisory)
Frequently asked questions
- What is CVE-2025-34256?
- CVE-2025-34256 is a critical-severity vulnerability in Advantech Wise-Deviceon Server, classified under Use of Hard-coded Cryptographic Key. CVSS score: 9.8/10. Published 2025-12-05.
- How severe is CVE-2025-34256?
- Critical severity. CVSS v3 base score is 9.8 out of 10.