| Package | Affected versions | Patched versions |
|---|---|---|
| open-webui | < 0.6.19 | 0.6.19 |
| open webui | < 0.6.19 | 0.6.19 |
There's an IDOR in the channels message management system that allows authenticated users to modify or delete any message within channels they have read access to. The vulnerability exists in the message update and delete endpoints, which implement channel-level authorization but completely lack message ownership validation.
While the frontend correctly implements ownership checks (showing edit/delete buttons only for message owners or admins), the backend APIs bypass these protections by only validating channel access permissions without verifying that the requesting user owns the target message. This creates a client-side security control bypass where attackers can directly call the APIs to modify other users' messages.
The vulnerability affects both message content modification and deletion, allowing users to tamper with message integrity and audit trails in collaborative channel environments.
Source: User-controlled message_id parameter in URL path
Call Chain:
update_message_by_id() (line 450) and delete_message_by_id() (line 630) in backend/open_webui/routers/channels.pyhas_access(user.id, type="read", access_control=channel.access_control) at lines 457 and 637Messages.get_message_by_id(message_id) at lines 467 and 647if message.channel_id != id: at lines 472 and 652message.user_id == user.id)Messages.update_message_by_id(message_id, form_data) at line 476 or Messages.delete_message_by_id(message_id) at line 658 - modifies any message without ownership verificationENABLE_CHANNELS=true)Message Update:
curl -X POST "http://localhost:8080/api/v1/channels/{channel_id}/messages/{victim_message_id}/update" \
-H "Authorization: Bearer {attacker_token}" \
-H "Content-Type: application/json" \
-d '{"content": "Malicious content injected by attacker"}'
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Scan my site freeMessage Deletion:
curl -X DELETE "http://localhost:8080/api/v1/channels/{channel_id}/messages/{victim_message_id}/delete" \
-H "Authorization: Bearer {attacker_token}"
Implement proper message ownership validation in the update and delete endpoints by adding ownership checks that follow the established security pattern used throughout the codebase. First, add a validation condition after the existing message retrieval to ensure only message owners or admins can modify messages: if user.role != "admin" and message.user_id != user.id and not has_access(user.id, type="write", access_control=channel.access_control) then raise a 403 Forbidden exception. Second, change the existing permission check from type="read" to type="write" for both update and delete operations to align with the access control model used in other routers (notes, prompts, knowledge, etc.).