Snipe-IT: Cross-company asset maintenance re-parenting via API update

Snipe-IT is an IT asset/license management system. Prior to 8.6.2, PATCH or PUT /api/v1/maintenances/{maintenance_id} checks access to the current maintenance record and asset but then fills attacker-controlled fields including asset_id without re-authorizing the newly supplied asset, allowing an authorized user to move a maintenance record onto an asset outside their company scope. This issue is fixed in version 8.6.2.