WireMock is a tool for mocking HTTP services. When certain request URLs like “@127.0.0.1:1234" are used in WireMock Studio configuration fields, the request might be forwarded to an arbitrary service reachable from WireMock’s instance. There are 3 identified potential attack vectors: via “TestRequester” functionality, webhooks and the proxy mode. As we can control HTTP Method, HTTP Headers, HTTP Data, it allows sending requests with the default level of credentials for the WireMock instance. The vendor has discontinued the affected Wiremock studio product and there will be no fix. Users are advised to find alternatives.