CVE-2024-45046

MEDIUM5.4EPSS 0.33%

PhpSpreadsheet HTML writer is vulnerable to Cross-Site Scripting via style information

Published: 8/29/2024Modified: 3/6/2025

Description

### 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](https://github.com/PHPOffice/PhpSpreadsheet/files/15212797/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.

Affected packages (2)

CVSS scores

SourceVersionSeverityVector
osvCVSS 4.0CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
osvCVSS 3.1MEDIUM5.4CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N

References (5)