SOCFortress CoPilot: Cross-Tenant Arbitrary Object-Store Write via the Data-Store Upload Endpoint (customer_user)

SOCFortress CoPilot focuses on providing a single pane of glass for all your security operations needs. Prior to 0.1.76, POST /api/agent_data_store/upload in backend/app/data_store/data_store_routes.py permits customer_user callers to choose bucket_name and object_name without an allowlist, tenant prefix, ownership check or content restriction. The only file check requires a nonempty filename. The operations in backend/app/data_store/data_store_operations.py create missing buckets and upsert objects, allowing existing objects belonging to any tenant to be overwritten. Targets include sysmon-configs/<customer_code>/sysmon_config.xml distributed to managed Windows endpoints, copilot-case-report-templates/<name> rendered server-side, and case evidence or forensic artifacts under copilot-cases/<case_id>/<file> and velociraptor-artifacts/<agent_id>/<flow_id>/<file>. A lowest-privilege user can tamper with cross-tenant evidence, blind endpoint telemetry, poison report templates for later code execution, plant data or exhaust storage. Sibling list, download and delete routes remain restricted to admin/analyst; the exposed operation is the upload write path. This issue is fixed in version 0.1.76.