PT-2026-46889 · Packagist · Shopware/Core+1

Published

2026-06-04

·

Updated

2026-06-04

·

CVE-2026-48013

CVSS v3.1

4.1

Medium

VectorAV:N/AC:L/PR:H/UI:N/S:C/C:L/I:N/A:N

Summary

The /api/ action/media/external-link endpoint allows authenticated admin users to make server-side HTTP HEAD requests to arbitrary internal IP addresses. While the parallel uploadFromURL flow validates target IPs against private/reserved ranges via FileUrlValidator, the linkURL flow only performs a URL format check (regex for http:// or https:// prefix), allowing SSRF to internal network services and cloud metadata endpoints.

Details

The vulnerability is an inconsistency between two URL-handling flows in MediaUploadService.
Vulnerable path (external-link):
MediaUploadV2Controller::externalLink() at src/Core/Content/Media/Api/MediaUploadV2Controller.php:66 takes a user-supplied url parameter and passes it to MediaUploadService::linkURL() at src/Core/Content/Media/Upload/MediaUploadService.php:134.
linkURL() calls getContentSizeFromValidExternalUrl($url) at line 159, which only validates via validateExternalUrl():
// src/Core/Content/Media/Upload/MediaUploadService.php:207-212
public static function validateExternalUrl(string $url): void
{
  if (!preg match('/^https?://.+/', $url)) {
    throw MediaException::invalidUrl($url);
  }
}
Then makes a server-side HEAD request with no IP filtering:
// src/Core/Content/Media/Upload/MediaUploadService.php:292-300
private function getContentSizeFromValidExternalUrl(string $url): int
{
  $this->validateExternalUrl($url);

  $headers = $this->httpClient->request('HEAD', $url)->getHeaders();
  if (!array key exists('content-length', $headers)) {
    throw MediaException::fileNotFound($url);
  }

  return (int) $headers['content-length'][0];
}
Protected path (upload by url):
In contrast, uploadFromURL uses FileFetcher::fetchFromURL() which calls FileUrlValidator::isValid():
// src/Core/Content/Media/File/FileFetcher.php:64
if ($this->enableUrlValidation && !$this->fileUrlValidator->isValid($url)) {
  throw MediaException::illegalUrl($url);
}
FileUrlValidator::isValid() resolves the hostname via gethostbyname() and validates the IP against private and reserved ranges using filter var() with FILTER FLAG NO PRIV RANGE | FILTER FLAG NO RES RANGE. This protection is entirely absent from the linkURL flow.

Impact

An authenticated admin user can:
  1. Probe cloud metadata services — HEAD requests to 169.254.169.254 reveal whether cloud metadata endpoints exist and leak content-length values
  2. Scan internal networks — Differentiate open/closed/filtered ports on internal hosts (10.x, 172.16.x, 192.168.x) based on response timing and error types
  3. Leak internal service information — The fileSize field stored in the database reflects the content-length header from internal services
  4. Redirect-based escalation — Symfony HttpClient follows redirects by default (max redirects=20), allowing an attacker-controlled external server to redirect the HEAD request to arbitrary internal destinations
Impact is limited to information disclosure via HEAD requests. The admin authentication requirement (PR:H) reduces exploitability, but in multi-tenant or compromised-credential scenarios this allows network reconnaissance from the server's perspective.

Recommended Fix

Apply FileUrlValidator to the linkURL flow, consistent with the uploadFromURL flow. In MediaUploadService:
// src/Core/Content/Media/Upload/MediaUploadService.php

// Add constructor dependency:
private readonly FileUrlValidatorInterface $fileUrlValidator;

// In getContentSizeFromValidExternalUrl(), add IP validation:
private function getContentSizeFromValidExternalUrl(string $url): int
{
  $this->validateExternalUrl($url);

  if (!$this->fileUrlValidator->isValid($url)) {
    throw MediaException::illegalUrl($url);
  }

  $headers = $this->httpClient->request('HEAD', $url)->getHeaders();
  if (!array key exists('content-length', $headers)) {
    throw MediaException::fileNotFound($url);
  }

  return (int) $headers['content-length'][0];
}
Additionally, consider setting max redirects: 0 on the HttpClient request to prevent redirect-based SSRF bypasses.

Fix

SSRF

Weakness Enumeration

CWE-918

Related Identifiers

CVE-2026-48013
GHSA-GQ96-5PFX-F4VC

Affected Products

Shopware/Core
Shopware/Platform