djangoSIGE through 1.10 (commit a6fe7e8) contains a cross-site request forgery vulnerability that allows unauthenticated attackers to cancel sales or purchase orders on behalf of authenticated users by exploiting order-cancellation logic implemented inside HTTP GET method handlers in CancelarOrcamentoVendaView, CancelarPedidoVendaView, CancelarOrcamentoCompraView, and CancelarPedidoCompraView. Attackers can lure an authenticated victim with change_orcamentovenda or equivalent permissions to a page containing a cross-origin reference such as an img tag pointing to the cancellation endpoint, bypassing CSRF token validation entirely since Django's CsrfViewMiddleware only enforces CSRF checks on unsafe HTTP methods.