How the Mentioned CVE Works:
The CVE-2025-XXXX vulnerability in MODX (prior to version 3.1.0) allows authenticated users to exploit a cross-site scripting (XSS) flaw by uploading malicious SVG files as profile images. SVG files can contain embedded JavaScript, which is executed when the image is rendered in a victim’s browser. This occurs because MODX fails to properly sanitize or validate the SVG file content during the upload process. When another user views the attacker’s profile, the malicious JavaScript executes in their browser, potentially allowing the attacker to steal session cookies, redirect users, or perform other malicious actions.
DailyCVE Form:
Platform: MODX
Version: Prior to 3.1.0
Vulnerability: Cross-Site Scripting (XSS)
Severity: Low
Date: Mar 13, 2025
What Undercode Say:
Exploitation:
1. Exploit Code Example:
<svg xmlns="http://www.w3.org/2000/svg" onload="alert('XSS')"></svg>
Save the above code as an SVG file and upload it as a profile image in MODX.
2. Exploit Command:
Use a web proxy like Burp Suite to intercept the SVG file upload request and modify it to include malicious JavaScript.
3. Impact:
- Steal session cookies.
- Redirect users to malicious sites.
- Perform actions on behalf of the victim.
Protection:
1. Sanitization:
Implement server-side validation to sanitize SVG files by removing JavaScript content.
$svgContent = file_get_contents($uploadedFile);
$svgContent = preg_replace('/<script.?>.?<\/script>/is', '', $svgContent);
file_put_contents($uploadedFile, $svgContent);
2. Content Security Policy (CSP):
Add a CSP header to restrict the execution of inline scripts.
Content-Security-Policy: default-src 'self'; script-src 'self';
3. Update MODX:
Upgrade to MODX version 3.1.0 or later, where this vulnerability is patched.
4. File Upload Restrictions:
Restrict file uploads to only trusted file types and use libraries like `libxml` to validate SVG files.
libxml_use_internal_errors(true);
$doc = new DOMDocument();
$doc->loadXML($svgContent);
if (libxml_get_errors()) {
// Invalid SVG file
}
5. Logging and Monitoring:
Monitor file uploads and log suspicious activities for further investigation.
tail -f /var/log/modx/upload.log
6. User Education:
Educate users about the risks of uploading untrusted files and encourage them to report suspicious activities.
By following these steps, you can mitigate the risk of CVE-2025-XXXX and protect your MODX installation from similar vulnerabilities.
References:
Reported By: https://github.com/advisories/GHSA-hm54-fg2w-2g6j
Extra Source Hub:
Undercode
