New Privilege Escalation Flaw Affects Most Linux Distributions

An Indian security researcher has discovered a highly critical flaw in X.Org Server package that impacts OpenBSD and most Linux distributions, including Debian, Ubuntu, CentOS, Red Hat, and Fedora. Xorg X server is a popular open-source implementation of the X11 system (display server) that offers a graphical environment to a wider range of hardware and OS platforms. It serves as an intermediary between client and user applications to manage graphical displays.

Xorg X server doesn't correctly handle and validate arguments for at least two command-line parameters, allowing a low-privileged user to execute malicious code and overwrite any file—including files owned by privileged users like root. The flaw, tracked as CVE-2018-14665, was introduced in X.Org server 1.19.0 package that remained undetected for almost two years and could have been exploited by a local attacker on the terminal or via SSH to elevate their privileges on a target system.

Security researcher Matthew Hickey shared an easy to execute proof-of-concept exploit code earlier today on Twitter, saying "An attacker can literally take over impacted systems with 3 commands or less."

The X.Org foundation has now released X.Org Server version 1.20.3 with security patches to address the issue.