GHSA-w388-2392-px73 praisonai-platform: Missing authorization on member removal enables full workspace takeover by any user regardless of role

• PyPI praisonai-platform: < 0.1.4 → fixed in 0.1.4

Summary Type: Authorization bypass enabling owner lockout. The `DELETE /workspaces/{workspace_id}/members/{user_id}` endpoint is gated only by `require_workspace_member(workspace_id)` (default `min_role="member"`). Any member can remove any other member, including the workspace owner, using a single DELETE. There is no caller-role check, no target-role check, no "cannot remove last owner" guard. File: `src/praisonai-platform/praisonai_platform/api/routes/workspaces.py`, lines 130-140; `services/member_service.py`, lines 71-78. Root cause: `MemberService.remove(workspace_id, user_id)` performs the deletion without any caller-permission check or owner-protection logic. The route accepts the URL-supplied `user_id` and dispatches it straight through. The role hierarchy (`MemberService.has_role`) is implemented but never invoked here. A member-tier attacker can issue `DELETE .../members/` and immediately lock the legitimate owner out of the workspace. Affected Code File 1: `src/praisonai-platform/praisonai_platform/api/routes/workspaces.py`, lines 130-140. ```python @router.delete("/{workspace_id}/members/{user_id}", status_code=status.HTTP_204_NO_CONTENT) async def remove_member( workspace_id: str, user_id: str, user: AuthIdentity = Depends(require_workspace_member), # bool: """Remove a member from a workspace.""" member = await self.get(workspace_id, user_id) if member is None: return False await self._session.delete(member) # `. State: control flow enters `remove_member`. 4. `require_workspace_member(W, attacker)` passes (attacker is a member). `MemberService.remove(W, O_id)` deletes the owner's member row. State: `Member(workspace_id=W, user_id=O_id, role="owner")` is gone. 5. Owner attempts `GET /workspaces/W/...` and `require_workspace_member(W, O_id)` returns 403. State: legitimate owner is now locked out of their own workspace. 6. Combined with the `update_member_role` companion advisory, the attacker first promotes themselves to owner, then removes the legitimate owner, then has uncontested control. Combined with `delete_workspace`, the attacker wipes the workspace after kicking the owner. 7. Final state: with one member-level token, the attacker locks the legitimate owner out of their own workspace permanently. The owner has no recourse other than database-level admin intervention. Security Impact Severity: sec-high. CVSS 8.1: network attack, low complexity, low privileges, no user interaction, scope unchanged, no confidentiality, high integrity (membership table corrupted), high availability (legitimate owner cannot access their own workspace). Attacker capability: with one workspace-member token plus one DELETE request, the attacker permanently locks any other member (including the workspace owner) out of the workspace. Preconditions: `praisonai-platform` is deployed multi-tenant; attacker has any membership token; owner's user_id is reachable via the (unauthenticated-for-member) `list_members` endpoint. Differential: source-inspection-verified. The asymmetry between `require_workspace_member`'s tunable `min_role` parameter and this endpoint's use of the default value confirms the gap. With the suggested fix below, member-tier tokens fail the gate, and removing the workspace's last owner triggers the additional guard. Suggested Fix ```diff --- a/src/praisonai-platform/praisonai_platform/api/routes/workspaces.py +++ b/src/praisonai-platform/praisonai_platform/api/routes/workspaces.py @@ -130,11 +130,21 @@ @router.delete("/{workspace_id}/members/{user_id}", status_code=status.HTTP_204_NO_CONTENT) async def remove_member( workspace_id: str, user_id: str, • user: AuthIdentity = Depends(require_workspace_member), + user: AuthIdentity = Depends(_require_workspace_owner), session: AsyncSession = Depends(get_db), ): member_svc = MemberService(session) + target = await member_svc.get(workspace_id, user_id) + if target is not None and target.role == "owner": + # Refuse to remove the last owner. + owners = [m for m in await member_svc.list_members(workspace_id) if m.role == "owner"] + if len(owners) <= 1: + raise HTTPException(status_code=409, detail="Cannot remove the last workspace owner") removed = await member_svc.remove(workspace_id, user_id) if not removed: raise HTTPException(status_code=404, detail="Member not found") ``` The four companion workspace-mutation endpoints exhibit the same default-min-role gap and are filed as their own advisories.