Skip to content

fix(upload): enforce size/type limits and derive storage path server-side #4

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Open
eltociear wants to merge 1 commit into
base: main
Choose a base branch
from
Open

fix(upload): enforce size/type limits and derive storage path server-side #4

Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
40 changes: 35 additions & 5 deletions app/api/upload/route.ts
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -4,11 +4,28 @@ export const dynamic = 'force-dynamic'

const ALLOWED_BUCKETS = ['software-logos', 'software-images']

// This route uses the service-role client (bypasses storage RLS) with no
// session/ownership check, since anonymous visitors legitimately upload a
// logo/screenshot while submitting a new listing (see src/views/Submit.tsx).
// That's fine, but the request body was otherwise fully attacker-controlled:
// no size cap, no content-type allowlist, and the storage key itself came
// straight from the client instead of being derived server-side. Any caller
// hitting this endpoint directly (skipping the frontend) could write
// arbitrary content/size to any key in these buckets, unlike every other
// mutating endpoint in this codebase.
const ALLOWED_TYPES: Record<string, string> = {
'image/png': 'png',
'image/jpeg': 'jpg',
'image/webp': 'webp',
'image/gif': 'gif',
'image/svg+xml': 'svg',
}
const MAX_FILE_BYTES = 5 * 1024 * 1024 // 5MB

export async function POST(req: Request) {
try {
const form = await req.formData()
const bucket = form.get('bucket')
const path = form.get('path')
const file = form.get('file')

if (typeof bucket !== 'string' || !ALLOWED_BUCKETS.includes(bucket)) {
Expand All @@ -18,20 +35,33 @@ export async function POST(req: Request) {
})
}

if (typeof path !== 'string' || !path) {
return new Response(JSON.stringify({ error: 'path is required' }), {
if (!(file instanceof File)) {
return new Response(JSON.stringify({ error: 'file is required' }), {
status: 400,
headers: { 'Content-Type': 'application/json' },
})
}

if (!(file instanceof File)) {
return new Response(JSON.stringify({ error: 'file is required' }), {
const ext = ALLOWED_TYPES[file.type]
if (!ext) {
return new Response(JSON.stringify({ error: 'Unsupported file type' }), {
status: 400,
headers: { 'Content-Type': 'application/json' },
})
}

if (file.size > MAX_FILE_BYTES) {
return new Response(JSON.stringify({ error: 'File too large (max 5MB)' }), {
status: 400,
headers: { 'Content-Type': 'application/json' },
})
}

// Derive the storage key server-side instead of trusting a client-supplied
// path, so a caller can't collide with/squat another upload's key or write
// outside the intended flat filename pattern.
const path = `${Date.now()}-${crypto.randomUUID()}.${ext}`

const { error } = await getSupabaseAdmin()
.storage.from(bucket)
.upload(path, file, { upsert: false, contentType: file.type })
Expand Down