CVE-2021-32739

Icinga is a monitoring system which checks the availability of network
resources, notifies users of outages, and generates performance data for
reporting. From version 2.4.0 through version 2.12.4, a vulnerability
exists that may allow privilege escalation for authenticated API users.
With a read-ony user’s credentials, an attacker can view most attributes of
all config objects including ticket_salt of ApiListener. This salt is
enough to compute a ticket for every possible common name (CN). A ticket,
the master node’s certificate, and a self-signed certificate are enough to
successfully request the desired certificate from Icinga. That certificate
may in turn be used to steal an endpoint or API user’s identity. Versions
2.12.5 and 2.11.10 both contain a fix the vulnerability. As a workaround,
one may either specify queryable types explicitly or filter out ApiListener
objects.