Loading a malicious hook library can lead to local privilege escalation

Kea configuration and API directives can be used to load a malicious hook library. Many common configurations run Kea as root, leave the API entry points unsecured by default, and/or place the control sockets in insecure paths. This issue affects Kea versions 2.4.0 through 2.4.1, 2.6.0 through 2.6.2, and 2.7.0 through 2.7.8.