PGV-264210H - FUXA's scheduler API missing admin check enables operator-to-admin escalation via scheduled device actionsDisclosed on June 08, 2026 (updated June 09, 2026)
PGV-264210H is a category 3 vulnerabilty that affects fuxa-server, versions ≤ 1.1.14-1243
The risk assessment shows that this vulnerability is exlpoited by a rogue user. A legitimate user who abuses authorized access to exploit this vulnerability.
The impact is contained to the application. Exploitation remains confined to the application and cannot affect the host environment or external systems.
The threat damage is caused by a denial of service (limited). Exploitation can degrade or intermittently disrupt application availability without causing a full outage.is caused by a data breach (limited). Exploitation does not provide access to data beyond what the user is already authorized to access.is caused by data tampering (limited). Exploitation does not allow modification of data beyond what the user is already authorized to modify.
An authorization issue in the Scheduler API allowed authenticated non-admin users to create or modify scheduled actions that should be restricted to administrators.
The Scheduler API did not correctly enforce administrator permissions when processing scheduler modifications.
As a result, authenticated users with non-administrative roles could create or modify scheduled actions that execute privileged operations, including device value changes and server-side script execution.
The issue was fixed in version 1.3.2 by enforcing the appropriate permission checks for scheduler modifications.
An operator-level user in FUXA reaches the PLC-write and server-side-script-execution surface that the platform otherwise restricts to administrators. In a SCADA deployment those two privileges cover setpoint control and the automation scripting engine. Alice schedules a job that rewrites a pump's enable tag, opens a safety interlock, or runs a project script that walks the device tree. The scheduled-action model extends the attack: Alice does not need to keep a session open for the action to fire, and a repeating schedule re-applies her changes every cycle even if an admin reverts them manually.
CVSS 3.1: AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L (Medium, 6.3). CWE-862.
Add authJwt.haveAdminPermission(permission) to both POST /api/scheduler and DELETE /api/scheduler, matching every other write endpoint that reaches runtime.devices.setTagValue or runtime.scriptsMgr.runScript.
schedulerApp.post("/api/scheduler", secureFnc, function(req, res) {
if (res.statusCode === 403) {
runtime.logger.error("api post scheduler: Tocken Expired");
return;
}
const permission = checkGroupsFnc(req);
const isGuest = authJwt.isGuestUser(req.userId, req.userGroups);
if (runtime.settings?.secureEnabled && (isGuest || !authJwt.haveAdminPermission(permission))) {
res.status(401).json({error:"unauthorized_error", message: "Unauthorized!"});
runtime.logger.error("api post scheduler: admin permission required");
return;
}
// ... rest unchanged ...
});
Apply the same change to the delete handler at server/api/scheduler/index.js:102-112. As defense in depth, the scheduler service should also validate each deviceActions entry against the creator's stored groups before execution (e.g., reject onRunScript on any scheduler whose author is not an admin at execution time).
A fix is available at https://github.com/frangoteam/FUXA/releases/tag/v1.3.2.
Found by aisafe.io
| Network Exposure | External Accessable from the public internet |
| Access Interface | WebBrowser Primarily web-based applications |
| Service Outage | Disruptive Operations would be impacted |
| Data Breach | Disruptive Operations would be impacted |
| Data Tampering | Disruptive Operations would be impacted |
| Customize | |
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