file-access-vuln

file-access-vuln is a skill for Claude Code, Codex from miru-zero/zero-brain. It costs 46 tokens per session (346 once invoked), scanned A, a copy of file-access-vuln, MIT.

A security-testing guide for workflows that read, upload, process, preview, share, or download files. It helps distinguish path traversal and local file inclusion from unsafe upload or file-processing problems.

In plain words
What is it for?
Use it to assess download endpoints, filename and path parameters, upload validation, archive extraction, previews, storage, sharing, and proxied file access.
Why use it?
File features can expose private files or create unsafe processing paths, and the relevant weakness may occur when a file is accepted, stored, processed, or served.

Skill for Claude CodeCodex

Install

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.

agentmods
npx agentmods add skills/miru-zero/zero-brain/file-access-vuln
Any agent
npx skills add miru-zero/zero-brain --skill file-access-vuln
Clone the repo
git clone --depth 1 https://github.com/miru-zero/zero-brain

Made for: Claude Code, Codex.

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 file-access-vuln

README.md
[![agentmods](https://agentmods.dev/badge/skills/miru-zero/zero-brain/file-access-vuln.svg)](https://agentmods.dev/skills/miru-zero/zero-brain/file-access-vuln)
Your own site
<a href="https://agentmods.dev/skills/miru-zero/zero-brain/file-access-vuln"><img src="https://agentmods.dev/badge/skills/miru-zero/zero-brain/file-access-vuln.svg" alt="Measured on agentmods" height="20"></a>
Per session 46 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 346 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin 95% 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 $0.00046 $0.00346
Opus 5 $0.00023 $0.00173
Sonnet 5 $0.00009 $0.00069
Haiku 4.5 $0.00005 $0.00035

Measured 5d ago against content hash 1632df329fb0, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-05, from the pricing page.

Security

Grade A, and why

file-access-vuln 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 5d 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.

Origin

This is a copy

95% identical to file-access-vuln — 6 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/file-access-vuln/SKILL.md · 31 lines

What it actually says

File Access Router

This is the routing entry point for filesystem paths, download endpoints, upload pipelines, and file preview handling.

When to Use

  • Parameters, filenames, download endpoints, or import flows influence file paths
  • The target supports upload, preview, transcoding, extraction, sharing, download, or proxied file access
  • You need to decide whether this is path traversal/LFI or an upload-validation/processing-chain issue

Skill Map

  • Path Traversal LFI: path traversal, file read, wrapper abuse, include chains
  • Upload Insecure Files: upload validation, storage paths, processing chains, overwrite risk, preview/share boundaries
  1. First identify whether the entry point is a path parameter, download endpoint, or upload workflow
  2. Then locate whether the issue appears in accept, store, process, or serve stages
  3. Small path-chain and upload-bypass samples are merged into the main topic skills; no separate payload entry is needed
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. 5d ago First seen · 31 lines · 46 tokens per session scan A 1632df329fb0

Subscribe to this mod's changes

file-access-vuln is a skill published in the GitHub repository miru-zero/zero-brain (0 stars, last pushed 18d ago), licensed MIT. It adds 46 tokens to every session and 346 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it A with 0 findings. It is 95% identical to file-access-vuln, differing in 6 lines, and is treated as a copy.

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