Know every vulnerabilitybefore it knows you.
DevGuard continuously monitors your dependencies and alerts you when CVEs like this one affect your stack — with real-time threat intelligence built for developers.
GHSA-jmpx-686v-c3wx
No affected components available
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)
The vulnerability can be exploited over the network without needing physical access. It is easy for an attacker to exploit this vulnerability. An attacker does not need any special privileges or access rights. The attacker needs the user to perform some action, like clicking a link. The impact is confined to the system where the vulnerability exists. There is a low impact on the confidentiality of the information. There is a high impact on the integrity of the data.
Exploitation attempts have been detected. Elevated vigilance and prompt remediation are advised.
The exploit probability is very low. The vulnerability is unlikely to be exploited in the next 30 days.
We did not find any exploit available. Neither in GitHub repositories nor in the Exploit-Database.
Browse More
Continuously monitor your dependencies and get alerted when vulnerabilities like this one affect your stack.
Checkout DevGuard