Host Header Injection
High · Injection · CWE-644
Description
App trusts Host header for links/password reset.
Root cause
Using Host in URL generation without validation.
Impact
Password reset poisoning, SSRF, cache poison.
Detection
Send alternate Host headers in lab.
Mitigation
Allow-list Host; use configured canonical host.
Secure coding
Generate URLs from config, not raw Host.
Safe lab example
Host header labs
Practise related skills in Labs or deepen on Academy library.