XRDP: Exploiting Unauthenticated X Windows Sessions

Executive Summary: This blog post explains techniques and proof-of-concept tooling to find and exploit unauthenticated X11 (X Window System) sessions. The authors present XRDP, a Python wrapper that automates window discovery, screen viewing, and input injection (using xwininfo, xwatchwin, xwd, xdotool) to obtain interactive access and spawn a reverse shell, and an nmap script (x11-active-displays) to detect active displays and capture screenshots. They tested scanning country-level ranges and found only a few vulnerable hosts, and published the tools on GitHub.