Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform. From 0.8.12 before 0.10.0, an authenticated non-admin user with read access to an arena wrapper model can reach a restricted underlying model through task endpoints such as /api/v1/tasks/moa/completions. The normal chat route resolves arena models before the final chat dispatch and therefore re-checks the selected underlying model. The task routes call utils.chat.generate_chat_completion() directly. In that direct path, arena fallback resolution happens after the wrapper access check and then recurses with bypass_filter=True, skipping the selected submodel's access check. This issue is fixed in version 0.10.0.
Exploitability
AV:NAC:LPR:LUI:NScope
S:UImpact
C:LI:NA:L5.4/CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:LAccess Control