CVE-2021-3902

Description

An improper restriction of external entities (XXE) vulnerability in dompdf/dompdf's SVG parser allows for Server-Side Request Forgery (SSRF) and deserialization attacks. This issue affects all versions prior to 2.0.0. The vulnerability can be exploited even if the isRemoteEnabled option is set to false. It allows attackers to perform SSRF, disclose internal image files, and cause PHAR deserialization attacks.

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CVSS v3.1 Score

9.8

CRITICAL

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

Weakness Type (CWE)

CWE-611 CWE-611

Affected Products

Vendor	Product	Versions
dompdf_project	dompdf	< 2.0.0

References

Advisories & Patches

https://github.com/dompdf/dompdf/commit/f56bc8e40be6c0ae0825e6c7396f4db80620b799 https://huntr.com/bounties/a6071c07-806f-429a-8656-a4742e4191b1

Exploits

https://huntr.com/bounties/a6071c07-806f-429a-8656-a4742e4191b1

Frequently Asked Questions

What is CVE-2021-3902? +

An improper restriction of external entities (XXE) vulnerability in dompdf/dompdf's SVG parser allows for Server-Side Request Forgery (SSRF) and deserialization attacks. This issue affects all versions prior to 2.0.0. The vulnerability can be exploited even if the isRemoteEnabled option is set to false. It allows attackers to perform SSRF, disclose internal image files, and cause PHAR deserialization attacks. It has a CVSS v3.1 base score of 9.8 (CRITICAL).

How severe is CVE-2021-3902? +

CVE-2021-3902 has a CVSS v3.1 score of 9.8 out of 10, rated CRITICAL. This is a critical vulnerability that should be patched immediately.

What products are affected by CVE-2021-3902? +

CVE-2021-3902 affects products from dompdf_project, specifically: dompdf. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2021-3902? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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