secsys-fdu/cve-2025-51863Proof-of-concept for a Self-XSS vulnerability in ChatGPTUtil, demonstrating cookie theft and account hijacking via crafted SVG payloads pasted into the chat interface.
ChatGPTUtil is a AI-powered chatbot assistant, providing access to both ChatGPT and an AI image generator. A Self Cross-Site Scripting (Self-XSS) vulnerability exists in the chat component. This can lead to cookie theft leading to remote account hijacking.
The attack vector is the Network. To exploit this XSS vulnerability, an attacker must craft a malicious payload (i.e., an SVG XSS payload) and deliver it to the victim (e.g., via email, a malicious website, a forum post, or an instant message). The attack occurs when the victim pastes the payload into the ChatGPTUtil chat interface. The POC as following:
<svg xmlns="http://www.w3.org/2000/svg" version="1.1"><circle cx="100" cy="50" r="40" stroke="black" stroke-width="2" fill="red" /> <script>alert(document.cookie)</script></svg>
This vulnerability can have an impact on any user of https://www.chatgptunli.com. The cookie (contains the session and token) of user will be stolen when pastes the payload into the chat interface.