file-access-vuln — Claude Code skill: file access vulnerability router
A routing skill for testing download endpoints, file paths, LFI and upload flows. It points the agent at the right topic skill.
npx skills add yaklang/hack-skills --skill file-access-vuln -a claude-codeWhat file-access-vuln does
This is the entry point for the file access category. The skill does not exploit anything by itself. It looks at the target and decides whether you are dealing with path traversal and local file inclusion, or with upload validation and the processing chain. From there the agent moves into path-traversal-lfi or upload-insecure-files.
Reach for it when parameters, filenames, download endpoints or import flows influence a file path. Also when the target supports upload, preview, transcoding, archive extraction, sharing or proxied file access. The flow it recommends: first identify whether the entry point is a path parameter, a download endpoint or an upload workflow. Then locate the stage where the issue shows up — accept, store, process or serve. There is no separate payload skill; short path-chain and upload-bypass samples live inside the main topic skills.
The router does not do the checking for you. If you have not pinned down which stage breaks, it just hands you to a neighbouring category such as injection-checking or business-logic-vuln. That is a hint to map the data flow by hand first.
What it helps with
- tell path traversal apart from an upload validation gap
- find the stage where file handling breaks
- choose between path traversal and an upload chain
- check preview and sharing flows for access boundaries
- map the data flow before throwing payloads at it
Example prompts for the agent
- look at this download endpoint — is it path traversal or an upload issue?
- test the file upload and preview chain on this target
- trace the filename parameter in the import flow, where does it lead?
How to install file-access-vuln
1Skills CLI (Vercel)
npx skills add yaklang/hack-skills --skill file-access-vuln -a claude-code2Manually: put the files in place
~/.claude/skills/file-access-vuln/SKILL.mdCopy the whole skill folder; for one project use .claude/skills/file-access-vuln/
1Skills CLI (Vercel)
npx skills add yaklang/hack-skills --skill file-access-vuln -a codex2Manually: put the files in place
.agents/skills/file-access-vuln/SKILL.mdFor all projects use ~/.agents/skills/
1Skills CLI (Vercel)
npx skills add yaklang/hack-skills --skill file-access-vuln -a cursor2Manually: put the files in place
.cursor/skills/file-access-vuln/SKILL.mdCursor also reads .agents/skills/ and .claude/skills/
1GitHub CLI
gh skill install yaklang/hack-skills file-access-vuln2Manually: put the files in place
.github/skills/file-access-vuln/SKILL.md1Skills CLI (Vercel)
npx skills add yaklang/hack-skills --skill file-access-vuln -a gemini-cli2Platform CLI
gemini skills install https://github.com/yaklang/hack-skills --path skills/file-access-vulnManually: put the files in place
.devin/skills/file-access-vuln/SKILL.mdThe legacy .windsurf/skills/ path still works
Skills CLI (Vercel)
npx skills add yaklang/hack-skills --skill file-access-vuln -a opencodeClaude.ai
Zip the folder and upload it in Settings → Capabilities → Skills
Step by step, with commands for each platform: How to install skills in Claude Code: five ways
Questions about file-access-vuln
How do I install file-access-vuln in Claude?
Run npx skills add yaklang/hack-skills --skill file-access-vuln -a claude-code. The skill lands in ~/.claude/skills/file-access-vuln/SKILL.md.
What does file-access-vuln do?
It is the category router: it works out whether you are facing a path and LFI problem or an upload and processing problem, then sends you to the matching topic skill.
How is it different from path-traversal-lfi and upload-insecure-files?
The router carries no exploitation techniques of its own. path-traversal-lfi covers path traversal, file reads and include chains, while upload-insecure-files covers upload validation, storage paths and processing chains.
Source text
SKILL.md · MIT
--- name: file-access-vuln description: >- Entry P1 category router for file access and upload workflows. Use when testing download endpoints, file paths, local file inclusion, upload flows, preview pipelines, archive extraction, or storage and sharing boundaries. --- # 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-lfi/SKILL.md): path traversal, file read, wrapper abuse, include chains - [Upload Insecure Files](../upload-insecure-files/SKILL.md): upload validation, storage paths, processing chains, overwrite risk, preview/share boundaries ## Recommended Flow 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 ## Related Categories - [injection-checking](../injection-checking/SKILL.md) - [business-logic-vuln](../business-logic-vuln/SKILL.md)
© yaklang · MIT · yaklang/hack-skills
