Open WebUI: Realtime endpoints accept Redis-revoked JWTs after signout/backchannel logout

Summary

With Redis configured, Open WebUI supports JWT revocation: POST /api/v1/auths/signout (per-token jti) and OIDC back-channel logout (per-user revoked_at) record revocations in Redis, and HTTP auth (get_current_user) rejects revoked tokens with 401. The realtime authentication surfaces do not perform this check: Socket.IO connect / user-join / join-channels / join-note and the terminal websocket first-message auth validate tokens with decode_token() only (signature + expiry). A JWT revoked by sign-out or back-channel logout therefore continues to authenticate new realtime connections, even though the same token is rejected on HTTP.

Affected component

• backend/open_webui/socket/main.py — Socket.IO connect, user-join, join-channels, join-note
• backend/open_webui/routers/terminals.py — terminal websocket first-message auth
• backend/open_webui/utils/auth.py — the revocation check was applied to HTTP only

Root cause

HTTP auth enforces revocation:

# utils/auth.py — get_current_user
if data.get('jti') and not await is_valid_token(request, data):
    raise HTTPException(status_code=401, detail='Invalid token')

Realtime auth calls decode_token() only, which verifies signature + expiry but never consults the Redis revocation keys ({prefix}:auth:token:{jti}:revoked, {prefix}:auth:user:{id}:revoked_at):

# socket/main.py — connect / user-join / join-channels / join-note
data = decode_token(auth['token'])
# routers/terminals.py — _resolve_authenticated_connection
data = decode_token(token)

Impact

A JWT revoked by user sign-out or OIDC back-channel logout still authenticates new realtime connections. A stolen token therefore retains realtime access after the victim signs out or the IdP performs back-channel logout — the very remediation for a compromised token. The token can populate SESSION_POOL as the victim, join their user/channel/note rooms (receiving realtime channel messages, collaborative-note updates and presence), drive socket-level collaboration as the victim, and pass terminal websocket authentication when terminal servers are configured. HTTP remains correctly protected (401), so REST data and state-changing REST endpoints are not reachable with the revoked token.

Proof of Concept

Reporter PoC on a Redis-backed deployment (v0.9.6 and main): after POST /api/v1/auths/signout, HTTP returns 401 for the token while a Socket.IO user-join with the same token still authenticates, and the terminal WS reaches terminal-server lookup rather than rejecting it as Invalid token.

Fix

Apply the revocation check on the realtime paths. The logic is factored into is_token_revoked(redis, decoded) (covering per-token jti and per-user revoked_at); the Socket.IO handlers and the terminal WS reject tokens that fail it, using the main app Redis where revocations are stored. HTTP is_valid_token delegates to the same helper, so HTTP behaviour is unchanged.

Affected / Patched

• Affected: >= 0.9.0, < 0.10.0, and only when Redis is configured (without Redis, per-token revocation is not supported and sign-out does not invalidate JWTs by design).
• Patched: v0.10.0. The revocation check (is_valid_token, covering per-token jti and per-user revoked_at) is applied on Socket.IO connect / user-join / join-channels / join-note and the terminal websocket first-message auth, using the main app Redis where revocations are stored. HTTP is_valid_token delegates to the same logic, so HTTP behaviour is unchanged.