A cross-site scripting (XSS) vulnerability in MantisBT before 2.1.1 allows remote attackers to inject arbitrary HTML or JavaScript (if MantisBT's CSP settings permit it) by modifying 'window_title' in the application configuration. This requires privileged access to MantisBT configuration management pages (i.e., administrator access rights) or altering the system configuration file (config_inc.php).
