Deserialization of Untrusted Data in dompdf/dompdf

Impact

DomPDF before version 2.0.0 is vulnerable to PHAR (PHP Archive) deserialization due to a lack of checking on the protocol before passing it into the file_get_contents() function. An attacker who can upload files of any type to the server can pass in the phar:// protocol to unserialize the uploaded file and instantiate arbitrary PHP objects. This can lead to remote code execution, especially when DOMPdf is used with frameworks with documented POP chains like Laravel or vulnerable developer code.

Affected packages

Start with the recorded fix for your release branch. Check your installed version and test compatibility before upgrading. Fixing this advisory does not rule out other vulnerabilities in the release.

Original source description

References

• Security advisory nvd.nist.gov/vuln/detail/CVE-2021-3838
• Patch github.com/dompdf/dompdf/commit/99aeec1efec9213e87098d42eb09439e7ee0bb6a
• Source reference github.com/dompdf/dompdf
• Source reference huntr.com/bounties/0bdddc12-ff67-4815-ab9f-6011a974f48e