GHSA-jmpx-686v-c3wx
PhpSpreadsheet allows unauthorized Reflected XSS in the constructor of the Downloader class
Quick fix
GHSA-jmpx-686v-c3wx — phpoffice/phpspreadsheet: upgrade to the fixed version with the command below.
composer require phpoffice/phpspreadsheet:^3.7.0Details
# Unauthorized Reflected XSS in the constructor of the `Downloader` class
**Product**: Phpspreadsheet **Version**: version 3.6.0 **CWE-ID**: CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') **CVSS vector v.3.1**: 8.2 (AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:H/A:N) **CVSS vector v.4.0**: 8.3 (AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:H/VA:N/SC:L/SI:H/SA:L) **Description**: using the `/vendor/phpoffice/phpspreadsheet/samples/download.php` script, an attacker can perform a XSS-type attack **Impact**: execution of arbitrary JavaScript code in the browser **Vulnerable component**: the constructor of the `Downloader` class **Exploitation conditions**: an unauthorized user **Mitigation**: sanitization of the `name` and `type` variables **Researcher**: Aleksey Solovev (Positive Technologies)
# Research
The researcher discovered zero-day vulnerability Unauthorized Reflected Cross-Site Scripting (XSS) (in the constructor of the `Downloader` class) in Phpspreadsheet.
The latest version (3.6.0) of the `phpoffice/phpspreadsheet` library was installed. The installation was carried out with the inclusion of examples.
*Listing 1. Installing the `phpoffice/phpspreadsheet` library* ``` $ composer require phpoffice/phpspreadsheet --prefer-source ```
The `./vendor/phpoffice/phpspreadsheet/samples/download.php` file processes the GET parameters `name` and `type`.

*Figure 1. The `./vendor/phpoffice/phpspreadsheet/samples/download.php` file accepts GET parameters.*
Consider the constructor of the `Downloader` class, where GET parameters are passed. Error is displayed without sanitization using GET parameters transmitted from the user.

*Figure 2. Error is displayed without sanitization*
When clicking on the following link, arbitrary JavaScript code will be executed.
*Listing 2.* ``` https://192.***.***.***/vendor/phpoffice/phpspreadsheet/samples/download.php?name=%3Cimg%20src=1%20onerror=alert()%3E&type=1 ```
Demonstration of the execution of arbitrary JavaScript code.
<img width="537" alt="fig3" src="https://github.com/user-attachments/assets/745d6e21-396f-4357-8ff8-e856adf15fee" />
*Figure 3. Executing arbitrary JavaScript code*
# Credit This vulnerability was discovered by **Aleksey Solovev (Positive Technologies)**
Are you affected?
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Affected packages
3.0.0Fixed in: 3.7.0composer require phpoffice/phpspreadsheet:^3.7.00Fixed in: 1.29.7composer require phpoffice/phpspreadsheet:^1.29.72.0.0Fixed in: 2.1.6composer require phpoffice/phpspreadsheet:^2.1.62.2.0Fixed in: 2.3.5composer require phpoffice/phpspreadsheet:^2.3.50No fixed version published yet for phpoffice/phpexcel (composer). Pin to a known-safe version or switch to an alternative.
References
- https://github.com/PHPOffice/PhpSpreadsheet/security/advisories/GHSA-jmpx-686v-c3wx[WEB]
- https://nvd.nist.gov/vuln/detail/CVE-2024-56365[ADVISORY]
- https://github.com/PHPOffice/PhpSpreadsheet/commit/700a80346be269af668914172bc6f4521982d0b4#diff-fbb0f53a5c68eeeffaa9ab35552c0b01740396f1a4045af5d2935ec2a62a7816[WEB]
- https://github.com/PHPOffice/PhpSpreadsheet[PACKAGE]