A Cross-Site Request Forgery (CSRF) in the System Halt API (/system/halt) of OPNsense Community Edition before 23.7 and Business Edition before 23.4.2 allows attackers to cause a Denial of Service (DoS) via a crafted GET request.
https://logicaltrust.net/blog/2023/08/opnsense.html
https://github.com/opnsense/core/commit/5d68f43d1f254144831881fc87d885eed120cf3c