Executive brief
FUXA is a web-based industrial control system visualization tool used for process monitoring and automation in SCADA/HMI environments. When authentication is enabled but the administrator fails to configure a JWT secret, the application accepts tokens signed with a publicly known hardcoded key, allowing an unauthenticated attacker to forge valid credentials, gain full administrative access, and execute arbitrary code on the server. This poses a critical risk to industrial operations and connected control systems.
Technical details
This vulnerability stems from an insecure default configuration in FUXA versions up to 1.2.9 where the JWT secret configuration option was only available via manual configuration file editing, not through the UI. When administrators enable authentication without explicitly setting a custom JWT secret, the application falls back to a hardcoded default key. An unauthenticated, remote attacker can exploit this by crafting and signing JWT tokens using the publicly known secret, completely bypassing all authentication controls. Once authenticated as an administrator, the attacker gains access to administrative APIs designed for automation and scripting, enabling arbitrary code execution in the context of the FUXA service. Depending on deployment configuration and system permissions, this can result in full system compromise and potential compromise of connected industrial control systems. The vulnerability has been patched in FUXA version 1.2.10, which enforces JWT secret configuration when enabling authentication and provides UI-based configuration options.
Affected products
- frangoteam FUXA <= 1.2.9
Timeline
- 2026-02-05: disclosed: GHSA-32cc-x95p-fxcg published
- 2026-01-24: patched: Fix committed; patched in v1.2.10 released 2026-01-25