Pi-hole Blind Server-Side Request Forgery (SSRF) vulnerability can lead to Remote Code Execution (RCE)

Pi-hole is a DNS sinkhole that protects devices from unwanted content without installing any client-side software. A vulnerability in versions prior to 5.18.3 allows an authenticated user to make internal requests to the server via the `gravity_DownloadBlocklistFromUrl()` function. Depending on some circumstances, the vulnerability could lead to remote command execution. Version 5.18.3 contains a patch for this issue.