securityScan() in PHPOffice PhpSpreadsheet through 1.5.0 allows a bypass of protection mechanisms for XXE via UTF-7 encoding in a .xlsx file

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.

This affects the package phpoffice/phpspreadsheet from 0.0.0. The library is vulnerable to XSS when creating an html output from an excel file by adding a comment on any cell. The root cause of this issue is within the HTML writer where user comments are concatenated as part of link and this is returned as HTML. A fix for this issue is available on commit 0ed5b800be2136bcb8fa9c1bdf59abc957a98845/master branch.

PhpSpreadsheet is a PHP library for reading and writing spreadsheet files. Versions prior to 3.7.0, 2.3.5, 2.1.6, and 1.29.7 have no sanitization in the `/vendor/phpoffice/phpspreadsheet/samples/Engineering/Convert-Online.php` file, which leads to the possibility of a cross-site scripting attack. Versions 3.7.0, 2.3.5, 2.1.6, and 1.29.7 contain a patch for the issue.

PhpSpreadsheet is a PHP library for reading and writing spreadsheet files. Versions prior to 3.7.0, 2.3.5, 2.1.6, and 1.29.7 have a cross-site scripting (XSS) vulnerability of the hyperlink base in the HTML page header. The HTML page is formed without sanitizing the hyperlink base. Versions 3.7.0, 2.3.5, 2.1.6, and 1.29.7 contain a patch for the issue.

PhpSpreadsheet is a PHP library for reading and writing spreadsheet files. Versions prior to 3.7.0, 2.3.5, 2.1.6, and 1.29.7 are vulnerable to bypass of the cross-site scripting sanitizer using the javascript protocol and special characters. An attacker can use special characters, so that the library processes the javascript protocol with special characters and generates an HTML link. Versions 3.7.0, 2.3.5, 2.1.6, and 1.29.7 contain a patch for the issue.

PhpSpreadsheet is a PHP library for reading and writing spreadsheet files. Cross-Site Scripting (XSS) vulnerability in the code which translates the XLSX file into a HTML representation and displays it in the response.