CVE-2021-3838

Dompdf remote code execution

9.8 CRITICALEPSS 1.43%

Published15 Nov 2024

Description

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.

CVSS 3.1 breakdown

Attack vectorNetwork

Attack complexityLow

Privileges requiredNone

User interactionNone

ScopeUnchanged

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

Dompdf< 2.0.0

Remediation

Fixed in

Dompdf≥ 2.0.0

Frequently asked

Is CVE-2021-3838 being actively exploited?

CVE-2021-3838 is not in the CISA KEV catalog. Its EPSS exploit probability is 1.43%.

How severe is CVE-2021-3838?

CVE-2021-3838 has a CVSS 3.1 base score of 9.8, rated critical. EPSS estimates a 1.43% probability of exploitation.

Which products are affected by CVE-2021-3838?

Affected products include Dompdf.

How do I fix CVE-2021-3838?

Upgrade affected software to a fixed version, for example Dompdf 2.0.0 or later, then confirm no affected versions remain in your inventory.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2021-3838 against the real software inventory on every managed device, every day. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

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Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.