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.

References

• https://nvd.nist.gov/vuln/detail/CVE-2020-14971
• pi-hole/web#1443
• pi-hole/web@8f6e136
• pi-hole/web@c949516
• https://blog.telspace.co.za/2020/06/pi-hole-code-injection-cve-2020-14971.html