refactor(storage): tighten S3 endpoint URL validation (#9668)

app/Livewire/Storage/Create.php

@@ -3,6 +3,7 @@
 namespace App\Livewire\Storage;
 
 use App\Models\S3Storage;
+use App\Rules\SafeWebhookUrl;
 use App\Support\ValidationPatterns;
 use Illuminate\Foundation\Auth\Access\AuthorizesRequests;
 use Illuminate\Support\Uri;
@@ -37,7 +38,7 @@ protected function rules(): array
             'key' => 'required|max:255',
             'secret' => 'required|max:255',
             'bucket' => 'required|max:255',
-            'endpoint' => 'required|url|max:255',
+            'endpoint' => ['required', 'max:255', new SafeWebhookUrl],
         ];
     }
 
@@ -55,7 +56,6 @@ protected function messages(): array
                 'bucket.required' => 'The Bucket field is required.',
                 'bucket.max' => 'The Bucket may not be greater than 255 characters.',
                 'endpoint.required' => 'The Endpoint field is required.',
-                'endpoint.url' => 'The Endpoint must be a valid URL.',
                 'endpoint.max' => 'The Endpoint may not be greater than 255 characters.',
             ]
         );

app/Livewire/Storage/Form.php

@@ -3,6 +3,7 @@
 namespace App\Livewire\Storage;
 
 use App\Models\S3Storage;
+use App\Rules\SafeWebhookUrl;
 use App\Support\ValidationPatterns;
 use Illuminate\Foundation\Auth\Access\AuthorizesRequests;
 use Illuminate\Support\Facades\DB;
@@ -42,7 +43,7 @@ protected function rules(): array
             'key' => 'required|max:255',
             'secret' => 'required|max:255',
             'bucket' => 'required|max:255',
-            'endpoint' => 'required|url|max:255',
+            'endpoint' => ['required', 'max:255', new SafeWebhookUrl],
         ];
     }
 
@@ -60,7 +61,6 @@ protected function messages(): array
                 'bucket.required' => 'The Bucket field is required.',
                 'bucket.max' => 'The Bucket may not be greater than 255 characters.',
                 'endpoint.required' => 'The Endpoint field is required.',
-                'endpoint.url' => 'The Endpoint must be a valid URL.',
                 'endpoint.max' => 'The Endpoint may not be greater than 255 characters.',
             ]
         );

app/Models/S3Storage.php

@@ -2,11 +2,13 @@
 
 namespace App\Models;
 
+use App\Rules\SafeWebhookUrl;
 use App\Traits\HasSafeStringAttribute;
 use Illuminate\Database\Eloquent\Casts\Attribute;
 use Illuminate\Database\Eloquent\Factories\HasFactory;
 use Illuminate\Notifications\Messages\MailMessage;
 use Illuminate\Support\Facades\Storage;
+use Illuminate\Support\Facades\Validator;
 
 class S3Storage extends BaseModel
 {
@@ -139,6 +141,14 @@ protected function region(): Attribute
     public function testConnection(bool $shouldSave = false)
     {
         try {
+            $validator = Validator::make(
+                ['endpoint' => $this['endpoint']],
+                ['endpoint' => ['required', new SafeWebhookUrl]],
+            );
+            if ($validator->fails()) {
+                throw new \RuntimeException('S3 endpoint is not allowed: '.$validator->errors()->first('endpoint'));
+            }
+
             $disk = Storage::build([
                 'driver' => 's3',
                 'region' => $this['region'],

app/Rules/SafeWebhookUrl.php

@@ -40,9 +40,15 @@ public function validate(string $attribute, mixed $value, Closure $fail): void
 
         $host = strtolower($host);
 
+        // Strip IPv6 brackets (e.g. "[::1]" -> "::1") before IP checks so bracketed
+        // literals can't sneak past filter_var FILTER_VALIDATE_IP.
+        $hostForIpCheck = (str_starts_with($host, '[') && str_ends_with($host, ']'))
+            ? substr($host, 1, -1)
+            : $host;
+
         // Block well-known dangerous hostnames
         $blockedHosts = ['localhost', '0.0.0.0', '::1'];
-        if (in_array($host, $blockedHosts) || str_ends_with($host, '.internal')) {
+        if (in_array($hostForIpCheck, $blockedHosts) || str_ends_with($host, '.internal')) {
             Log::warning('Webhook URL points to blocked host', [
                 'attribute' => $attribute,
                 'host' => $host,
@@ -55,7 +61,7 @@ public function validate(string $attribute, mixed $value, Closure $fail): void
         }
 
         // Block loopback (127.0.0.0/8) and link-local/metadata (169.254.0.0/16) when IP is provided directly
-        if (filter_var($host, FILTER_VALIDATE_IP) && ($this->isLoopback($host) || $this->isLinkLocal($host))) {
+        if (filter_var($hostForIpCheck, FILTER_VALIDATE_IP) && ($this->isLoopback($hostForIpCheck) || $this->isLinkLocal($hostForIpCheck))) {
             Log::warning('Webhook URL points to blocked IP range', [
                 'attribute' => $attribute,
                 'host' => $host,

tests/Unit/S3StorageEndpointValidationTest.php

@@ -0,0 +1,91 @@
+<?php
+
+use App\Models\S3Storage;
+use App\Rules\SafeWebhookUrl;
+use Illuminate\Support\Facades\Validator;
+use Tests\TestCase;
+
+uses(TestCase::class);
+
+/**
+ * Regression tests for GHSA-pwm4-w33c-wjf3 — SSRF via S3 Storage endpoint.
+ *
+ * The Livewire forms (Create.php, Form.php) and the model-level defense in
+ * S3Storage::testConnection() share the same SafeWebhookUrl rule. These tests
+ * assert the rule rejects the concrete payloads from the advisory PoC and
+ * that the model refuses to build an S3 client for an unsafe endpoint.
+ */
+it('rejects SSRF payloads from the GHSA-pwm4-w33c-wjf3 advisory', function (string $endpoint) {
+    $validator = Validator::make(
+        ['endpoint' => $endpoint],
+        ['endpoint' => ['required', 'max:255', new SafeWebhookUrl]],
+    );
+
+    expect($validator->fails())->toBeTrue("Expected rejection: {$endpoint}");
+})->with([
+    'AWS IMDS' => 'http://169.254.169.254/latest/meta-data/',
+    'AWS IMDS bare' => 'http://169.254.169.254',
+    'GCP metadata via link-local' => 'http://169.254.0.1',
+    'loopback v4' => 'http://127.0.0.1',
+    'loopback Redis' => 'http://127.0.0.1:6379',
+    'loopback Postgres' => 'http://127.0.0.1:5432',
+    'loopback alt in /8' => 'http://127.10.20.30',
+    'zero address' => 'http://0.0.0.0',
+    'IPv6 loopback' => 'http://[::1]',
+    'localhost hostname' => 'http://localhost',
+    'localhost with port' => 'http://localhost:9000',
+    'internal suffix' => 'http://minio.internal',
+    'file scheme' => 'file:///etc/passwd',
+    'javascript scheme' => 'javascript:alert(1)',
+]);
+
+it('accepts real-world S3 endpoints', function (string $endpoint) {
+    $validator = Validator::make(
+        ['endpoint' => $endpoint],
+        ['endpoint' => ['required', 'max:255', new SafeWebhookUrl]],
+    );
+
+    expect($validator->passes())->toBeTrue("Expected accepted: {$endpoint}");
+})->with([
+    'AWS S3' => 'https://s3.us-east-1.amazonaws.com',
+    'Cloudflare R2' => 'https://fake.r2.cloudflarestorage.com',
+    'DigitalOcean Spaces' => 'https://nyc3.digitaloceanspaces.com',
+    'Backblaze B2' => 'https://s3.us-west-001.backblazeb2.com',
+    'Self-hosted MinIO on 10.x' => 'http://10.0.0.5:9000',
+    'Self-hosted MinIO on 172.16.x' => 'http://172.16.0.10:9000',
+    'Self-hosted MinIO on 192.168.x' => 'http://192.168.1.50:9000',
+    'Custom domain MinIO' => 'https://minio.example.com',
+]);
+
+it('blocks testConnection() on an unsafe endpoint without issuing HTTP', function () {
+    $s3Storage = new S3Storage;
+    $s3Storage->setRawAttributes([
+        'region' => 'us-east-1',
+        'key' => 'AKIAEXAMPLE',
+        'secret' => 'secret',
+        'bucket' => 'latest/meta-data',
+        'endpoint' => 'http://169.254.169.254',
+    ]);
+
+    expect(fn () => $s3Storage->testConnection())
+        ->toThrow(RuntimeException::class, 'S3 endpoint is not allowed');
+});
+
+it('blocks testConnection() for loopback endpoints', function (string $endpoint) {
+    $s3Storage = new S3Storage;
+    $s3Storage->setRawAttributes([
+        'region' => 'us-east-1',
+        'key' => 'AKIAEXAMPLE',
+        'secret' => 'secret',
+        'bucket' => 'bucket',
+        'endpoint' => $endpoint,
+    ]);
+
+    expect(fn () => $s3Storage->testConnection())
+        ->toThrow(RuntimeException::class, 'S3 endpoint is not allowed');
+})->with([
+    'http loopback' => 'http://127.0.0.1:6379',
+    'localhost' => 'http://localhost:9000',
+    'IPv6 loopback' => 'http://[::1]',
+    'internal TLD' => 'http://backend.internal',
+]);