CVE-2019-12331

HIGH8.8EPSS 0.12%

XXE in PHPSpreadsheet due to incomplete fix for previous encoding issue

Published: 11/20/2019Modified: 3/6/2025
Also known as:GHSA-vvwv-h69m-wg6f

Description

PHPOffice PhpSpreadsheet before 1.8.0 has an XXE issue. The XmlScanner decodes the sheet1.xml from an .xlsx to utf-8 if something else than UTF-8 is declared in the header. This was a security measurement to prevent CVE-2018-19277 but the fix is not sufficient. By double-encoding the the xml payload to utf-7 it is possible to bypass the check for the string ?<!ENTITY? and thus allowing for an xml external entity processing (XXE) attack.

Affected packages (2)

CVSS scores

SourceVersionSeverityVector
osvCVSS 3.1HIGH8.8CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

References (8)