X2Engine <= 4.1.7 (SiteController.php) PHP Object Injection Vulnerability

• Software Link:

http://www.x2engine.com/

• Affected Versions:

All versions from 2.8 to 4.1.7.

• Vulnerability Description:

The vulnerable code is located in the “actionSendErrorReport” method defined in /protected/controllers/SiteController.php:

    public function actionSendErrorReport(){
        if(isset($_POST['report'])){
            $errorReport = $_POST['report'];
            $errorReport = unserialize(base64_decode($errorReport));
            if(isset($_POST['email'])){
                $errorReport['email'] = $_POST['email'];
            }

User input passed through the “report” POST parameter is not properly sanitized before being used in a call to the “unserialize()” function at line 156. This can be exploited to inject arbitrary PHP objects into the application scope, and could allow an attacker to carry out Server-Side Request Forgery (SSRF) and possibly other attacks via specially crafted serialized objects.

• Solution:

Apply the vendor patch or update to version 4.2 or later.

• Disclosure Timeline:

[31/07/2014] – Vendor notified
[31/07/2014] – Vendor released security patch: http://x2community.com/?showtopic=1804
[01/08/2014] – CVE number requested
[16/08/2014] – CVE number assigned
[05/09/2014] – Version 4.2 released
[23/09/2014] – Public disclosure

• CVE Reference:

The Common Vulnerabilities and Exposures project (cve.mitre.org)
has assigned the name CVE-2014-5297 to this vulnerability.

• Credits:

Vulnerability discovered by Egidio Romano.