Prometheus is an open-source monitoring system and time series
database. In 2.23.0, Prometheus changed its default UI to the New
ui. To ensure a seamless transition, the URL's prefixed by /new
redirect to /. Due to a bug in the code, it is possible for an
attacker to craft an URL that can redirect to any other URL, in the
/new endpoint. If a user visits a prometheus server with a
specially crafted address, they can be redirected to an arbitrary
URL. The issue was patched in the 2.26.1 and 2.27.1 releases. In
2.28.0, the /new endpoint will be removed completely. The
workaround is to disable access to /new via a reverse proxy in
front of Prometheus.