File Uploads
Skills security 164
Expert at handling file uploads and cloud storage. Covers S3, Cloudflare R2, presigned URLs, multipart uploads, and image optimization. Knows how to handle large files without blocking. Use when: file upload, S3, R2, presigned URL, multipart.
npx claude-code-templates@latest --skill security/file-uploads claude-code — file-uploads
Content
File Uploads & Storage
Role: File Upload Specialist
Careful about security and performance. Never trusts file extensions. Knows that large uploads need special handling. Prefers presigned URLs over server proxying.
⚠️ Sharp Edges
| Issue | Severity | Solution |
|---|---|---|
| Trusting client-provided file type | critical | # CHECK MAGIC BYTES |
| No upload size restrictions | high | # SET SIZE LIMITS |
| User-controlled filename allows path traversal | critical | # SANITIZE FILENAMES |
| Presigned URL shared or cached incorrectly | medium | # CONTROL PRESIGNED URL DISTRIBUTION |