testing-for-host-header-injection

name	testing-for-host-header-injection
description	Test web applications for HTTP Host header injection vulnerabilities to identify password reset poisoning, web cache poisoning, SSRF, and virtual host routing manipulation risks.
domain	cybersecurity
subdomain	web-application-security
tags	["host-header-injection","password-reset-poisoning","cache-poisoning","virtual-host","web-security","header-manipulation","ssrf"]
version	1.0
author	mahipal
license	Apache-2.0
nist_csf	["PR.PS-01","ID.RA-01","PR.DS-10","DE.CM-01"]

Testing for Host Header Injection

When to Use

• When testing password reset functionality for token theft via host manipulation
• During assessment of web caching behavior influenced by Host header values
• When testing virtual host routing and server-side request processing
• During penetration testing of applications behind reverse proxies or load balancers
• When evaluating SSRF potential through Host header manipulation

Prerequisites

• Burp Suite for intercepting and modifying Host headers
• Understanding of HTTP Host header role in virtual hosting and routing
• Knowledge of alternative host headers (X-Forwarded-Host, X-Host, X-Original-URL)
• Access to an attacker-controlled domain for receiving poisoned requests
• Burp Collaborator or interact.sh for out-of-band detection
• Multiple test accounts for password reset testing

Legal Notice: This skill is for authorized security testing and educational purposes only. Unauthorized use against systems you do not own or have written permission to test is illegal and may violate computer fraud laws.

Workflow

Step 1 — Test Basic Host Header Injection

# Supply arbitrary Host header
curl -H "Host: evil.com" http://target.com/ -v
# Check if application reflects evil.com in response

# Double Host header
curl -H "Host: target.com" -H "Host: evil.com" http://target.com/ -v

# Host header with port injection
curl -H "Host: target.com:evil.com" http://target.com/ -v
curl -H "Host: target.com:@evil.com" http://target.com/ -v

# Absolute URL with different Host
curl --request-target "http://target.com/" -H "Host: evil.com" http://target.com/ -v

# Check for different virtual host access
curl -H "Host: admin.target.com" http://target.com/ -v
curl -H "Host: internal.target.com" http://target.com/ -v
curl -H "Host: localhost" http://target.com/ -v

Step 2 — Test Password Reset Poisoning

# Trigger password reset with modified Host header

curl -X POST http://target.com/forgot-password \
  -H  \
  -d 




curl -X POST http://target.com/forgot-password \
  -H  \
  -d 


curl -X POST http://target.com/forgot-password \
  -H  \
  -d 


 header       ; 
  curl -X POST http://target.com/forgot-password \
    -H  \
    -d