Description

Stored Cross-Site Scripting (XSS) vulnerability due to the lack of content validation and output encoding.

Proof of Concept

1.Access demo website https://demo.syspass.org and login with an account.

2.Create new account, in URL/IP field -> input https://google.com" onclick="alert(document.domain) -> payload will escape from href and title attribute -> Set permission to public for all account

3.Save account -> anyother accounts try to access the URL/IP asssigned to that account -> an alert box will pop up.

Image

Impact

1.Malicious JavaScript has access to all the same objects as the rest of the web page, including access to cookies and local storage, which are often used to store session tokens. If an attacker can obtain a user's session cookie, they can then impersonate that user.

2.Furthermore, JavaScript can read and make arbitrary modifications to the contents of a page being displayed to a user. Therefore, XSS in conjunction with some clever social engineering opens up a lot of possibilities for an attacker.