Deserialization in Dompdf Dompdf/dompdf

CVE-2021-3838

DomPDF before version 2.0.0 is vulnerable to PHAR 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.

Vulnerability class: Insecure Deserialization

EPSS: 0.014 (70.3th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2021-3838?
CVE-2021-3838 is a critical-severity vulnerability in Dompdf Dompdf/dompdf, classified under Deserialization of Untrusted Data. CVSS score: 9.8/10. Published 2024-11-15.
How severe is CVE-2021-3838?
Critical severity. CVSS v3 base score is 9.8 out of 10.
Is CVE-2021-3838 known to be exploited?
2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.