Description

PhpSpreadsheet is a PHP library for reading and writing spreadsheet files. The XmlScanner class has a scan method which should prevent XXE attacks. However, prior to versions 1.9.4, 2.1.3, 2.3.2, and 3.4.0, the regexes used in the `scan` method and the findCharSet method can be bypassed by using UCS-4 and encoding guessing. An attacker can bypass the sanitizer and achieve an XML external entity attack. Versions 1.9.4, 2.1.3, 2.3.2, and 3.4.0 fix the issue.

References

https://github.com/PHPOffice/PhpSpreadsheet/security/advisories/GHSA-jw4x-v69f-hh5w

https://github.com/PHPOffice/PhpSpreadsheet/blob/39fc51309181e82593b06e2fa8e45ef8333a0335/src/PhpSpreadsheet/Reader/Security/XmlScanner.php

https://owasp.org/www-community/vulnerabilities/XML_External_Entity_(XXE)_Processing

https://www.w3.org/TR/xml/#sec-guessing-no-ext-info

For More Information

CVERecord