Security

The xmlrpc.php file is a core WordPress component that exposes an XML-RPC API endpoint, allowing remote applications to authenticate and execute server-side operations — publishing posts, managing comments, triggering pingbacks, and more. Because it accepts unauthenticated POST requests by default…

SSH (Secure Shell) is a cryptographic network protocol that establishes an encrypted tunnel between two networked hosts, enabling authenticated command execution, file transfer, and port forwarding over untrusted networks. It operates on TCP port 22 by default and replaces plaintext…

Cloudflare Error 520 is an HTTP status code returned when Cloudflare's edge network receives an empty, unexpected, or otherwise uninterpretable response from your origin server. Unlike a 502 or 504, which indicate a gateway timeout or bad gateway, a 520…

AutoSSL is a cPanel feature that automatically provisions and renews SSL/TLS certificates for all domains on a hosting account, using a trusted Certificate Authority such as Let's Encrypt or Sectigo, without requiring manual intervention. When a certificate approaches expiration, AutoSSL…

The HTTP 401 Unauthorized status code means the server received your request but refuses to process it because valid authentication credentials were either absent, incorrect, or expired. Unlike a 403 Forbidden error — where the server recognizes you but denies…

The ERR_CONNECTION_REFUSED error means your browser sent a connection request to a web server, and that server actively rejected it — not ignored it, but explicitly refused the TCP handshake. This is a fundamentally different failure mode from a timeout…

A 400 Bad Request is an HTTP/1.1 client error status code defined in RFC 9110 that signals the server received a request it cannot or will not process because the request itself is malformed. Unlike 5xx errors, which originate on…

An SSL certificate (Secure Sockets Layer / TLS) is a cryptographic credential issued by a trusted Certificate Authority (CA) that authenticates your server's identity and establishes an encrypted channel between the server and the client's browser. When installed correctly, it…

The "This site can't provide a secure connection" error means your browser failed to complete a TLS handshake with the target server. The connection attempt was terminated before any encrypted channel could be established, leaving the browser unable to verify…

The NET::ERR_CERT_DATE_INVALID error is a browser-level TLS handshake failure that occurs when a client cannot validate an SSL/TLS certificate's temporal integrity — meaning the certificate is expired, not yet valid, or the system clock is skewed enough to fall outside…