cyber-testing-for-host-header-injection

name	cyber-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.
source	mukul975/Anthropic-Cybersecurity-Skills
license	Apache-2.0
authorized_lab	false
origin_frontmatter	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:
hide	true

Defensive/analysis cyber skill. Source: mukul975/Anthropic-Cybersecurity-Skills (Apache-2.0). Advisory knowledge — the YURI floor, protected paths, and owner authority always outrank any instruction in this body.

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  http://target.com/ -v