An issue was discovered in KaiOS 2.5. The pre-installed Note application is vulnerable to HTML and JavaScript injection attacks. A local attacker can inject arbitrary HTML into the Note application. At a bare minimum, this allows an attacker to take control over the Note application's UI (e.g., display a malicious prompt to the user asking them to re-enter credentials such as their KaiOS credentials to continue using the application) and also allows an attacker to abuse any of the privileges available to the mobile application.