sunkaifei FlyCMS User Login Cross-Site Scripting Vulnerability

A cross-site scripting (XSS) vulnerability has been identified in sunkaifei FlyCMS versions prior to abbaa5a8daefb146ad4d61027035026b052cb414. The issue arises in the userLogin function of the UserController.java file, where the redirectUrl parameter is not properly sanitized before being outputted. This flaw allows remote attackers to execute XSS attacks, potentially leading to the theft of user credentials.

Impact

Exploitation of this vulnerability allows for reflected cross-site scripting, where an attacker can inject malicious scripts that are executed in the context of the user's browser.

Reproduction

To reproduce this vulnerability, send a GET request to the /login endpoint with a crafted redirectUrl parameter that includes a script payload. The application will reflect the unsanitized input, executing the script in the user's browser.