CVE-2024-45046

PHPSpreadsheet is a pure PHP library for reading and writing spreadsheet files. In affected versions \PhpOffice\PhpSpreadsheet\Writer\Html doesn't sanitize spreadsheet styling information such as font names, allowing an attacker to inject arbitrary JavaScript on the page. As a result an attacker may used a crafted spreadsheet to fully takeover a session of a user viewing spreadsheet files as HTML. This issue has been addressed in release version 2.1.0. All users are advised to upgrade. There are no known workarounds for this vulnerability.

PHPSpreadsheet is a pure PHP library for reading and writing spreadsheet files. In affected versions \PhpOffice\PhpSpreadsheet\Writer\Html doesn't sanitize spreadsheet styling information such as font names, allowing an attacker to inject arbitrary JavaScript on the page. As a result an attacker may used a crafted spreadsheet to fully takeover a session of a user viewing spreadsheet files as HTML. This issue has been addressed in release version 2.1.0. All users are advised to upgrade. There are no known workarounds for this vulnerability.

Summary

\PhpOffice\PhpSpreadsheet\Writer\Html doesn't sanitize spreadsheet styling information such as font names, allowing an attacker to inject arbitrary JavaScript on the page.

PoC

Example target script:

<?php

require 'vendor/autoload.php';

$reader = \PhpOffice\PhpSpreadsheet\IOFactory::createReader("Xlsx");
$spreadsheet = $reader->load(__DIR__ . '/book.xlsx');

$writer = new \PhpOffice\PhpSpreadsheet\Writer\Html($spreadsheet);
print($writer->generateHTMLAll());

Save this file in the same directory: book.xlsx

Open index.php in a web browser. An alert should be displayed.

Impact

Full takeover of the session of users viewing spreadsheet files as HTML.

PHPSpreadsheet is a pure PHP library for reading and writing spreadsheet files. In affected versions \PhpOffice\PhpSpreadsheet\Writer\Html doesn't sanitize spreadsheet styling information such as font names, allowing an attacker to inject arbitrary JavaScript on the page. As a result an attacker may used a crafted spreadsheet to fully takeover a session of a user viewing spreadsheet files as HTML. This issue has been addressed in release version 2.1.0. All users are advised to upgrade. There are no known workarounds for this vulnerability.

PHPSpreadsheet is a pure PHP library for reading and writing spreadsheet files. In affected versions \PhpOffice\PhpSpreadsheet\Writer\Html doesn't sanitize spreadsheet styling information such as font names, allowing an attacker to inject arbitrary JavaScript on the page. As a result an attacker may used a crafted spreadsheet to fully takeover a session of a user viewing spreadsheet files as HTML. This issue has been addressed in release version 2.1.0. All users are advised to upgrade. There are no known workarounds for this vulnerability.

Summary

\PhpOffice\PhpSpreadsheet\Writer\Html doesn't sanitize spreadsheet styling information such as font names, allowing an attacker to inject arbitrary JavaScript on the page.

PoC

Example target script:

<?php

require 'vendor/autoload.php';

$reader = \PhpOffice\PhpSpreadsheet\IOFactory::createReader("Xlsx");
$spreadsheet = $reader->load(__DIR__ . '/book.xlsx');

$writer = new \PhpOffice\PhpSpreadsheet\Writer\Html($spreadsheet);
print($writer->generateHTMLAll());

Save this file in the same directory: book.xlsx

Open index.php in a web browser. An alert should be displayed.

Impact

Full takeover of the session of users viewing spreadsheet files as HTML.