The issue is related to the proxy mode of WireMock, which can be protected by network restrictions configuration. However, when these restrictions are configured using domain names, the configuration is vulnerable to DNS rebinding attacks. The root cause of the attack is a defect in the logic that allows for a race condition triggered by a DNS server whose address expires between the initial validation and the outbound network request. Control over a DNS service is required to exploit this attack, resulting in high execution complexity and limited impact.