CVE-2024-56408: PhpSpreadsheet allows unauthorized reflected XSS in `Convert-Online.php` file
Unauthorized Reflected XSS in Convert-Online.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/Engineering/Convert-Online.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/Engineering/Convert-Online.php file Exploitation conditions: an unauthorized user Mitigation: sanitization of the quantity variable Researcher: Aleksey Solovev (Positive Technologies)
Research
The researcher discovered zero-day vulnerability Unauthorized Reflected Cross-Site Scripting (XSS) (in Convert-Online.php file) in Phpspreadsheet.
There is no sanitization in the /vendor/phpoffice/phpspreadsheet/samples/Engineering/Convert-Online.php file, which leads to the possibility of a XSS attack.
!fig4
Figure 4. The message with the quantity parameter is displayed without sanitization
The following figure shows a POST HTTP-request and a response to the server with the variable quantity, which is displayed in the response from the server without sanitization.
<img width="460" alt="fig5" src="https://github.com/user-attachments/assets/022323c9-ca1e-44ea-9380-37ed7848e971" />
Figure 5. In the server's response , the quantity variable is displayed without sanitization
An attacker can prepare a special HTML form that will be automatically sent to the vulnerable scenario.
Listing 3. 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/Engineering/Convert-Online.php" method="POST"> <input type="hidden" name="category" value="Weight and Mass" /> <input type="hidden" name="quantity" value="1.0<img src=1 onerror=alert()>" /> <input type="hidden" name="fromUnit" value="g" /> <input type="hidden" name="toUnit" value="g" /> <input type="hidden" name="submitx" value="Convert" /> <input type="submit" value="Submit request" /> </form> <script> history.pushState('', '', '/'); document.forms[0].submit(); </script> </body> </html>
After the user visits the attacker's resource, the form will be sent to the vulnerable scenario, which will lead to the execution of arbitrary code in the client's browser. <img width="389" alt="fig6" src="https://github.com/user-attachments/assets/e52b68c6-5a98-4db2-85ec-5bf37e4cb625" />
Figure 6. Executing arbitrary JavaScript code
Credit This vulnerability was discovered by Aleksey Solovev (Positive Technologies)
Other sources
PhpSpreadsheet is a PHP library for reading and writing spreadsheet files. Versions prior to 3.7.0, 2.3.5, 2.1.6, and 1.29.7 have no sanitization in the /vendor/phpoffice/phpspreadsheet/samples/Engineering/Convert-Online.php file, which leads to the possibility of a cross-site scripting attack. Versions 3.7.0, 2.3.5, 2.1.6, and 1.29.7 contain a patch for the issue.
— NVD
Affected Software
Remediation
Event History
Frequently Asked Questions
What is the severity of CVE-2024-56408?
CVE-2024-56408 has a CVSS score of 8.2, indicating a high severity level.
How do I fix CVE-2024-56408?
To fix CVE-2024-56408, upgrade to Phpspreadsheet version 3.7.0 or later, or the appropriate remedial versions listed in the advisory.
Which versions of Phpspreadsheet are affected by CVE-2024-56408?
CVE-2024-56408 affects Phpspreadsheet versions from 1.0.0 up to 3.6.0, inclusive.
What type of vulnerability is CVE-2024-56408?
CVE-2024-56408 is classified as an unauthorized reflected cross-site scripting (XSS) vulnerability.
Is user interaction required to exploit CVE-2024-56408?
Yes, CVE-2024-56408 requires user interaction to exploit the reflected XSS vulnerability.