使用反斜杠字符将请求重定向到外部主机(浏览器端打开重定向)

Proof of concept ([live link](https://response.ee/data/SFRUUC8xLjEgMjAwIE9LDQpDb250ZW50LVR5cGU6IHRleHQvaHRtbDsgY2hhcnNldD11dGYtOA0KDQo8IURPQ1RZUEUgaHRtbD4KPGhlYWQ-CjxzY3JpcHQgc3JjPSJodHRwczovL3VucGtnLmNvbS92dWVAMi43LjE2L2Rpc3QvdnVlLmpzIiBpbnRlZ3JpdHk9InNoYTM4NC1zbVZTNzhONjNHMHVGcFZIOWJLZGIrMllJVzdROWVGcmxlNzlpbW8rQVdXNllMbHVReEFFSzdreExPdDFiTmV4IiBjcm9zc29yaWdpbj0iYW5vbnltb3VzIj48L3NjcmlwdD4KPHNjcmlwdCBzcmM9Imh0dHBzOi8vdW5wa2cuY29tL3Z1ZS1yb3V0ZXJAMy42LjUvZGlzdC92dWUtcm91dGVyLmpzIiBpbnRlZ3JpdHk9InNoYTM4NC1Ja012UGJFQlRhWlh0RFA4WEtSMHZ6UXY2aDEybW4xVHNtMFlSemxKNXlaUXRRMGIwZkkydXBjM0VCNWVyU1dwIiBjcm9zc29yaWdpbj0iYW5vbnltb3VzIj48L3NjcmlwdD4KPC9oZWFkPgoKPGJvZHk-CjxkaXYgaWQ9ImFwcCI-CiAgPHA-CiAgICA8cm91dGVyLWxpbmsgdG89Ii9cZXhhbXBsZS5jb20iPkNhc2UgMTogJmx0O3JvdXRlci1saW5rIHRvPSIvXGV4YW1wbGUuY29tIiZndDs8L3JvdXRlci1saW5rPgogIDwvcD4KICA8cD4KICAgIDxhIGhyZWY9Ij9yZWRpcmVjdD0vXGV4YW1wbGUuY29tIj5DYXNlIDI6IHJvdXRlci5wdXNoKCIvXGV4YW1wbGUuY29tIik8L2E-CiAgPC9wPgo8L2Rpdj4KCjxzY3JpcHQ-CmNvbnN0IHJvdXRlciA9IG5ldyBWdWVSb3V0ZXIoewogIG1vZGU6ICJoaXN0b3J5IiwKICAvLyBiYXNlOiAiLyIgIC8vIG9yOiAiIgp9KTsKCi8qCi8vIFBhdGNoICh1c2UgYXQgb3duIHJpc2spCnJvdXRlci5iZWZvcmVFYWNoKCh0bywgZnJvbSwgbmV4dCkgPT4gewogIHRyeSB7CiAgICBjb25zdCB1cmwgPSBuZXcgVVJMKHRvLnBhdGgsIHdpb