Nezha Monitoring is a self-hostable, lightweight, servers and websites monitoring and O&M tool. From version 1.0.0 to before version 2.2.0, the getRedirectURL function in oauth2.go:22-29 constructs the OAuth2 callback URL by concatenating the request's Host header with a fixed path, with zero validation of the Host header. This can result in host header injection. This issue has been patched in version 2.2.0.
Exploitability
AV:NAC:HPR:NUI:RScope
S:UImpact
C:HI:HA:N6.8/CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:NInput Validation