Forge Uploads

forge-uploads: File uploads

Engine: Forge native

Purpose

Audit the complete upload, processing, storage, delivery, and deletion pipeline against hostile files.

Deterministic runtime composition

Before loading any provider procedure, run:

Resolve ../../runtime/cli/src/composition-entry.js relative to this SKILL.md, then run:

node "<resolved-absolute-runner-path>" uploads compose --workflow audit --root "<repository-root>" --dry-run --json

Add one repeatable --request <provider-or-source> flag for each explicit user request. Add --condition <task-condition> or --risk-surface <surface> only for a task fact you directly proved; never infer one from generic wording. The command above is the default for this audit-oriented module; for implementation use --workflow build, and for a fix, retest, or release gate use --workflow fix, verify, or ship respectively. Read the JSON response, keep the Forge contract at index zero, and resolve paths against the absolute runtime_root reported in that response. Read eager[].runtimePath when entering the module. The full selected[] list is availability/provenance; load only deferred[].runtimePath when the task reaches that concern, in tier order. Refuse any path that escapes the root. Respect every reported suppression and context budget. If missing is non-empty, stop and report the installation as damaged; do not improvise a prose fallback. The runner and specialist content may live in a plugin cache or global installation; never assume they are inside the audited repository.

Resolve and read ../fullstack-forge/references/shared/module-contract.md (applicability, execution, mutation, verification, completion) and ../fullstack-forge/references/shared/evidence-rules.md (statuses, standards, tools, findings via ../fullstack-forge/references/PROTOCOL.md) relative to this module SKILL.md before reporting.

Never hide failed checks or claim that an operation ran when it did not.

Automatic activation signals

Activate when a request or direct repository evidence involves file uploads, when the user explicitly names forge-uploads, or when discovery proves an applicable boundary.

• Direct or presigned uploads
• Imports, attachments, avatars, media, and generated files

When not to activate

• Systems with no file ingestion or user-controlled object references

Automated support

Relevant discovery inputs are:

• upload routes
• storage configuration
• processors and download paths

Deterministic support, bounded evidence only:

• inspect-upload-pipeline

Agent inspection procedure

1. Map the complete pipeline: entry points, validation layers, processing steps, storage destinations, and delivery paths.
2. Verify server-side validation order: authorization, then count and byte limits, then decoded content and signature checks — never extension or client MIME alone.
3. Trace where bytes rest at each stage; verify private-by-default quarantine before scanning and that scanner errors or timeouts fail closed.
4. Inspect object keys (server-generated, unguessable), tenant separation, signed-URL scope and expiry, and delivery headers (Content-Disposition, fixed Content-Type, nosniff).
5. Exercise hostile inputs where a fixture suite exists: polyglots, oversized files, archive bombs, and traversal names; verify cleanup of temporary, abandoned, and replaced objects.

Manual inspection requirements:

• Review provider bucket policy and malware-scanner failure mode
• Exercise polyglot, oversized, malformed, duplicate, and unauthorized objects

Stack-specific guidance:

• Do not trust client MIME or original filenames; validate after streaming limits

Evidence to collect

Standards used as criteria:

• OWASP File Upload Cheat Sheet
• OWASP ASVS 5.0

Common production failures

• Trace authorization, filename normalization, extension and MIME allowlists, signature detection, size and count limits
• Inspect archive bombs, path traversal, parser isolation, malware scanning, image re-encoding, metadata stripping, and quarantine
• Verify private storage, random object names, signed URL scope/expiry, download headers, tenant boundaries, cleanup, and orphan handling

Missing-control checks

Each item needs direct evidence or one reasoned status.

• Server-side extension allowlists
• Browser accept attributes as hints rather than proof
• MIME validation
• Magic-byte validation
• File-signature validation
• Extension and MIME mismatches
• File-count limits
• Per-file size limits
• Total request limits
• Decompressed-size limits
• Image dimensions
• Image pixel counts
• PDF page counts
• Archive entry limits
• Parser bombs
• ZIP bombs
• Decompression bombs
• Malformed documents
• Polyglot files
• Quarantine storage
• Malware scanning before release
• Scanner timeout behavior
• Scanner failure behavior that fails closed
• Scanner metadata
• File hashes
• Rescanning policy
• Malware alerts
• Permanent quarantine
• Deletion policy
• Administrative handling
• No untrusted files in executable directories or public application folders
• Server-generated object keys
• Original filenames never used as paths
• Private-by-default object storage
• Short-lived signed URLs
• Tenant and environment separation
• Authorization before signed-URL generation
• Unguessable object identifiers
• Public-indexing prevention
• Active-content rendering prevention
• Image decode and re-encode
• EXIF stripping
• Image dimension and pixel limits
• Safe thumbnails
• SVG sanitization or rejection
• Remote SVG reference prevention
• Embedded script prevention
• PDF JavaScript
• PDF embedded files
• PDF launch actions
• Document external references
• Interactive forms
• Macros and Office active content
• Sandboxed parsers and parser resource limits
• Safe preview generation
• Document normalization
• Hostile extracted text
• No execution of embedded content
• Filename normalization
• Unicode trick detection
• Control characters
• Path traversal
• Safe Content-Disposition
• Fixed Content-Type and X-Content-Type-Options nosniff
• No reflected filenames in HTML
• Unsafe formats not rendered inline
• Per-user, per-IP, and per-tenant limits
• Storage quotas
• Concurrent-upload limits
• Repeated processing attacks
• Many-small-files attacks
• Resource timeouts
• Parser isolation
• Monitoring and cleanup
• Temporary-file and abandoned-upload cleanup
• Orphan detection and replacement cleanup
• Account and tenant deletion
• Retention and backup behavior
• Log and signed-URL redaction
• Encryption

Commands and tools

• Run forge uploads audit --json or fullstack-forge uploads audit --json when an explicit audit is requested and the CLI is installed. Normal feature work does not require it.

Safe fixes

• Add explicit size/count limits and safe content-disposition
• Normalize generated object names and log redaction

Approval-required changes

• Changing bucket visibility, accepted types, retention, or processing architecture

Verification

• Run a hostile-file fixture suite through the real pipeline
• Confirm rejected and quarantined files are neither served nor orphaned

Completion contract

Follow fullstack-forge/references/shared/completion.md and the limitations below.

Known limitations

• Scanner effectiveness and storage policy need direct service evidence