Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add woohyun212/security-skill --skill web-vuln-http-smugglinggit clone --depth 1 https://github.com/woohyun212/security-skillWrote 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.
[](https://agentmods.dev/skills/woohyun212/security-skill/web-vuln-http-smuggling)<a href="https://agentmods.dev/skills/woohyun212/security-skill/web-vuln-http-smuggling"><img src="https://agentmods.dev/badge/skills/woohyun212/security-skill/web-vuln-http-smuggling/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.
<a href="https://agentmods.dev/skills/woohyun212/security-skill/web-vuln-http-smuggling"><img src="https://agentmods.dev/badge/skills/woohyun212/security-skill/web-vuln-http-smuggling.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00040 | $0.02735 |
| Opus 5 | $0.00020 | $0.01367 |
| Sonnet 5 | $0.00008 | $0.00547 |
| Haiku 4.5 | $0.00004 | $0.00274 |
Grade A, and why
web-vuln-http-smuggling 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 10d ago.
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.
- `curl` compiled with HTTP/1.1 support (standard on Linux/macOS) How it starts
The opening of the file, as written. The whole thing — 251 lines — stays where its author put it; the contents beside it link to each section on GitHub.
What this skill does
Detects HTTP request smuggling vulnerabilities by exploiting disagreements between front-end (reverse proxy/CDN) and back-end (application server) parsers over how to determine request boundaries. Tests CL.TE (Content-Length front, Transfer-Encoding back), TE.CL (Transfer-Encoding front, Content-Length back), TE.TE (both use Transfer-Encoding but with obfuscation), and H2.CL (HTTP/2 downgrade to HTTP/1.1) variants using timing-based probes and differential response analysis.
When to use
- When the target sits behind a reverse proxy, CDN, or load balancer (Nginx, HAProxy, AWS ALB, Cloudflare, Fastly)
- When testing for WAF bypass, request hijacking, cache poisoning, or credential theft
- During high-value bug bounty targets with multi-tier HTTP infrastructure
- When initial recon reveals
Via,X-Forwarded-For, orX-Cacheresponse headers indicating a proxy layer
Prerequisites
curlcompiled with HTTP/1.1 support (standard on Linux/macOS)netcat(nc) for raw TCP requests- Burp Suite with HTTP Request Smuggler extension (optional, for automated scanning)
- A test account on the target for differential response verification
Inputs
| Variable | Description | Example |
|---|---|---|
TARGET_HOST |
Target hostname | example.com |
TARGET_PORT |
Target port | 443 |
TARGET_PATH |
Path to test (preferably a POST-accepting endpoint) | /api/search |
AUTH_HEADER |
Authentication header if required | Authorization: Bearer eyJ... |
Workflow
Step 1: Identify front-end/back-end architecture
TARGET_HOST="example.com"
TARGET_PORT=443
TARGET_PATH="/api/search"
echo "=== Step 1: Architecture fingerprinting ==="
curl -s -I "https://$TARGET_HOST$TARGET_PATH" | grep -iE "via|x-cache|x-served-by|server|x-forwarded|cdn|cf-ray|x-amz"
echo ""
echo "Indicators of proxy presence:"
echo " See REFERENCE.md for proxy fingerprinting header-to-vendor mappings"
Reference: See REFERENCE.md for proxy fingerprinting indicators (header-to-vendor mappings).
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.
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.
- 10d ago First seen · 251 lines · 40 tokens per session scan A ca3b5e1dc92a
web-vuln-http-smuggling is a skill published in the GitHub repository woohyun212/security-skill (21 stars, last pushed 4mo ago), licensed MIT. It adds 40 tokens to every session and 2,735 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 1 finding (makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
Other skills, from other repositories
systematic-debugging
Use when encountering any bug, test failure, or unexpected behavior, before proposing fixes.
local-ai-agents
Build local-first AI agents that run entirely on a developer workstation with Microsoft Foundry Local and Qwen function-calling models. Covers Small Language Models (SLMs), the OpenAI-compatible local endpoint, sandboxed local tools, local RAG with Chroma, local MCP servers, hybrid cloud/local routing, and the…
next-cache-components-adoption
Turn on Cache Components in a Next.js app and resolve the blocking routes it surfaces. Use when the user wants to enable, adopt, or migrate to Cache Components, flip the cacheComponents flag, work through a flood of blocking-prerender / instant validation errors, run the cache-components-instant-false codemod, or…
insight-error-page
Write or audit an insight-kind error page for the Next.js dev overlay. Use when creating a new errors/ .mdx page, auditing an existing one, or checking that a page matches the framework fix cards. Covers page structure, title alignment, FixCard cards with Copy prompt button, code snippets, terminology verification…
next-cache-components-optimizer
Drive a Next.js route to instant navigation by setting up an agentic loop, under Cache Components / PPR, on initial load (hard navigation) and client-side navigation (soft navigation). Encode the goal as a failing @next/playwright instant() e2e and work it to green, one verified route at a time; the shipped test then…
next-partial-prefetching-adoption
Turn on Partial Prefetching in a Next.js app and work through the insights it surfaces. Use when the user wants to enable or adopt Partial Prefetching, flip the partialPrefetching flag, opt routes in with export const prefetch = 'partial', audit Link prefetch={true} behavior, preserve existing prefetched UI with…