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MCP: Relax redirectUri validation to allow any URI scheme #667

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MCP: Relax redirectUri validation to allow any URI scheme #667

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24 changes: 12 additions & 12 deletions src/routes/oauth/authorize.tsx
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Original file line number Diff line number Diff line change
Expand Up @@ -9,23 +9,23 @@ import { useIsDark } from '~/hooks/useIsDark'
import { BrandContextMenu } from '~/components/BrandContextMenu'

/**
* Validate redirect URI - must be localhost or HTTPS
* Validate redirect URI - block only HTTP to non-localhost
* Allows: HTTPS, localhost (any protocol), custom schemes (cursor://, vscode://, etc.)
* Inlined here to avoid pulling in server-only dependencies
*/
function validateRedirectUri(uri: string): boolean {
try {
const url = new URL(uri)
if (
url.hostname === 'localhost' ||
url.hostname === '127.0.0.1' ||
url.hostname === '[::1]'
) {
return true
// Block only HTTP to non-localhost
if (url.protocol === 'http:') {
return (
url.hostname === 'localhost' ||
url.hostname === '127.0.0.1' ||
url.hostname === '[::1]'
)
}
if (url.protocol === 'https:') {
return true
}
return false
// Allow everything else: HTTPS, custom schemes
return true
} catch {
return false
}
Expand Down Expand Up @@ -84,7 +84,7 @@ export const Route = createFileRoute('/oauth/authorize')({
if (!validateRedirectUri(deps.redirect_uri)) {
return {
error: 'invalid_request',
errorDescription: 'redirect_uri must be localhost or HTTPS',
errorDescription: 'HTTP redirect URIs are only allowed for localhost',
}
}

Expand Down
8 changes: 4 additions & 4 deletions src/routes/oauth/register.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -16,7 +16,7 @@ export const Route = createFileRoute('/oauth/register')({
// This is secure because:
// 1. Registration only generates deterministic client IDs
// 2. No secrets are issued (PKCE public clients)
// 3. Redirect URIs are validated for localhost or HTTPS
// 3. Redirect URIs block insecure HTTP to remote hosts
const origin = request.headers.get('Origin')
setResponseHeader('Content-Type', 'application/json')
setResponseHeader('Access-Control-Allow-Origin', origin || '*')
Expand All @@ -41,14 +41,14 @@ export const Route = createFileRoute('/oauth/register')({
url.hostname === 'localhost' ||
url.hostname === '127.0.0.1' ||
url.hostname === '[::1]'
const isHttps = url.protocol === 'https:'

if (!isLocalhost && !isHttps) {
// Block only HTTP to non-localhost (allows custom schemes like cursor://)
if (url.protocol === 'http:' && !isLocalhost) {
return new Response(
JSON.stringify({
error: 'invalid_redirect_uri',
error_description:
'Redirect URIs must be localhost or HTTPS',
'HTTP redirect URIs are only allowed for localhost',
}),
{ status: 400 },
)
Expand Down