ujcms 存在用户名枚举漏洞

未授权用户信息枚举漏洞
漏洞原因

com.ujcms.cms.core.web.api.UserController 中存在多个用于判断用户名、手机号及邮箱是否存在的接口，例如：

/username-exist
/username-not-exist
/mobile-exist
/mobile-not-exist
/email-exist
/email-not-exist

相关接口未进行有效的权限控制，攻击者无需登录即可访问。
漏洞位置：com.ujcms.cms.core.web.api.UserController

如图，多处接口无权限注解，默认可访问
本地复现：

Start in com.ujcms.cms.core.web.api.UserController and inspect the access annotations and behavior of the username-exist, username-not-exist, mobile-exist, mobile-not-exist, email-exist, and email-not-exist endpoints. Reproduce each request without logging in, then verify that unauthenticated users can no longer enumerate account information while the intended authorized behavior still works.

Written by the indexing model from the issue text.