CVE-2024-48917

PhpSpreadsheet is a PHP library for reading and writing spreadsheet files. The `XmlScanner` class has a scan method which should prevent XXE attacks. However, in a bypass of the previously reported `CVE-2024-47873`, the regexes from the `findCharSet` method, which is used for determining the current encoding can be bypassed by using a payload in the encoding UTF-7, and adding at end of the file a comment with the value `encoding="UTF-8"` with `"`, which is matched by the first regex, so that `encoding='UTF-7'` with single quotes `'` in the XML header is not matched by the second regex. 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.

The following products are affected by CVE-2024-48917 vulnerability.

Here, you will find a curated list of external links that provide in-depth information to CVE-2024-48917.

URL	Resource
https://github.com/PHPOffice/PhpSpreadsheet/blob/39fc51309181e82593b06e2fa8e45ef8333a0335/src/PhpSpreadsheet/Reader/Security/XmlScanner.php
https://github.com/PHPOffice/PhpSpreadsheet/security/advisories/GHSA-7cc9-j4mv-vcjp
https://owasp.org/www-community/vulnerabilities/XML_External_Entity_(XXE)_Processing