Name: CVE-2021-40439: Improper Restriction of XML External Entity Reference
Creator: Rapid7
Published: 2021-10-07T00:00:00.000Z
License: https://www.rapid7.com/legal/website-terms-of-use/
Keywords: CVE, CVE-2021-40439, CWE-611, CVSS 6.5, EPSS 0.00398

Apache OpenOffice has a dependency on expat software. Versions prior to 2.1.0 were subject to CVE-2013-0340 a "Billion Laughs" entity expansion denial of service attack and exploit via crafted XML files. ODF files consist of a set of XML files. All versions of Apache OpenOffice up to 4.1.10 are subject to this issue. expat in version 4.1.11 is patched.

CVSS Details

CVSS 3.1 Base Score: 6.5
CVSS 3.1 Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H)

Covered by Rapid7

Product	Vendor Advisory	Solution File	Added	Published
Apache Openoffice	—	Upgrade Apache OpenOffice to the latest version	Sep 12, 2025	Oct 7, 2021

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CVSS Details

Covered by Rapid7

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