Pi-hole through 5.0 allows code injection in piholedhcp (the Static DHCP Leases section) by modifying Teleporter backup files and then restoring them. This occurs in settings.php. To exploit this, an attacker would request a backup of limited files via teleporter.php. These are placed into a .tar.gz archive. The attacker then modifies the host parameter in dnsmasq.d files, and then compresses and uploads these files again.
CWE-862 - Missing Authorization
The missing authorization vulnerability occurs when a software program allows users to access privileged parts of the program without verifying the user credentials. Impact of such a vulnerability depends on the resources employed by the software, ranging from account takeover to sensitive information exposure, denial of service, and complete system takeover.