GHSA-vvwv-h69m-wg6fHighCVSS 8.8

XXE in PHPSpreadsheet due to incomplete fix for previous encoding issue

Published
November 20, 2019
Last Modified
March 6, 2025

🔗 CVE IDs covered (1)

📋 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 products2

  • composer/phpoffice/phpspreadsheet:< 1.8.0
  • composer/phpoffice/phpexcel:<= 1.8.2

🔗 References (8)