Summary Any authenticated user with access to a shared terminal server could get script of their choosing to run in the Open WebUI origin itself. The in-app port preview rendered the content of a previewed port in an iframe whose sandbox always granted allow-same-origin alongside allow-scripts, and that content is served from a path on the application's own origin, so the sandbox provided no isolation at all. Script served on a previewed port could read the victim's session token and take over the account.

Preconditions - At least one terminal server configured by an admin (TERMINALSERVERCONNECTIONS, empty by default) and reachable by both the attacker and the victim. Deployments with no terminal server configured are not affected. - The attacker needs a normal authenticated account with access to that terminal connection, no admin rights, plus the ability to start a process listening on a port there. - Personal terminals a user configures for themselves are not affected. Those carry an external URL, so the previewed document is cross-origin and the sandbox held. - The victim has to open the port list and click the attacker's port. - TERMINALPROXYHEADERS unset and no CONTENTSECURITYPOLICY set, which are the defaults. An operator who had already set a restrictive Content-Security-Policy through either was not exposed, since those headers apply to the proxied response. - The iframeSandboxAllowSameOrigin user setting is off by default, but the affected branch ignored it entirely.

Impact The previewed page runs in the application origin, so it can reach the parent window, read the session token out of localStorage and exfiltrate it, which is full account takeover of the victim. If the victim is an admin, or any user holding workspace.functions, that takeover extends to server-side code execution through Functions. Serving the page costs the attacker nothing beyond the terminal access they already hold, so the only real barrier is getting the victim to open that port. Instances with no terminal server configured were never affected, and neither were personal terminals pointed at an external URL.

Fix Fixed in 0.11.1 by 54d7a2237. The port preview now gates allow-same-origin behind a terminalPreviewAllowSameOrigin user setting that is off by default, so the preview loads at an opaque origin and cannot reach the parent context. Upgrading is sufficient and no configuration change is required. Previews of pages that need same-origin access still work if a user turns that setting on, and doing so re-enables the behaviour described here for that user.

Root cause - src/lib/components/chat/FileNav/PortPreview.svelte, the preview iframe, reached by clicking a port in the file navigator's port list. - Present from 0.8.11, the first release containing the component, through 0.11.0.

Every other iframe in the application had already been moved to an opt-in same-origin setting. The port preview kept a static sandbox string with allow-same-origin baked into it, and it was missed when the equivalent problem was fixed in the file preview for 0.11.0. Because the terminal proxy is mounted under the application's own origin and forwards the upstream response and its content type without adding a Content-Security-Policy of its own unless the operator configured one, and no global CSP is set, the sandbox was the only isolation boundary left, and it was granting precisely the permission that dissolved it.

Proof of concept On a terminal server the victim can also reach, serve an HTML page containing a script that reads window.parent.localStorage.token and sends it to a host the attacker controls. The victim opens the file navigator, switches to the port list and clicks that port. The preview opens, the script executes at the application origin, and the token is exfiltrated.

Credits Reported by @manus-use (researcher zx / Jace).

Summary

POST /api/v1/images/edit performed no authorization beyond requiring a verified account. Every other image-editing surface in Open WebUI enforces the global image-edit switch and the per-user image-generation permission — the /api/v1/images/generations route, the built-in editimage tool, and the chat image-edit middleware — but the direct edit route enforced neither. A verified non-admin user could therefore invoke server-side image editing, reaching the configured image-edit provider with the administrator's credentials, even when the administrator had globally disabled image editing (ENABLEIMAGEEDIT=False) or denied that user image-generation permission. The image-editing UI is surfaced only to administrators (Playground), so the route additionally exposed an admin-only capability to any verified user.

Impact

An authenticated, non-admin user can:

- bypass the global ENABLEIMAGEEDIT=False administrator control; - bypass a denied per-user/group features.imagegeneration permission; - cause the server to send billable image-edit requests to the configured provider (OpenAI-compatible, Gemini, or ComfyUI) using administrator-configured credentials (IMAGESEDITOPENAIAPIKEY for the OpenAI engine).

No cross-user data is exposed and the provider credentials are never returned to the caller; the impact is the control/permission bypass and the associated billable resource consumption.

Affected Versions

>= 0.8.11, < 0.10.0 (the /api/v1/images/edit route was introduced in 0.8.11 and was ungated from the outset). Fixed in v0.10.0.

Details

/api/v1/images/generations enforces ENABLEIMAGEGENERATION (403 if globally disabled) and features.imagegeneration (403 for non-admins without the permission). The editimage built-in tool and the chat image-edit middleware likewise gate on ENABLEIMAGEEDIT and features.imagegeneration. The direct POST /api/v1/images/edit route ran on Depends(getverifieduser) alone and proceeded straight to provider dispatch, applying none of these controls.

Proof of Concept

As a verified non-admin user, with image editing globally disabled (ENABLEIMAGEEDIT=False) or features.imagegeneration denied for the user:

http POST /api/v1/images/edit Authorization: Bearer <nonadminusertoken> Content-Type: application/json

{"image":"data:image/png;base64,<png>","prompt":"edit","model":"gpt-image-1"}

The request reaches the configured image-edit provider and returns an edited image despite the disabled control/permission.

Patch

The direct route is split from its shared implementation (mirroring generateimages/imagegenerations): a thin /edit route now enforces ENABLEIMAGEEDIT and the per-user features.imagegeneration permission before delegating to the shared imageedits() implementation. The internal callers (the editimage tool and the chat middleware) call the implementation directly and already gate themselves, so they are unaffected.