A vulnerability that is trivial to exploit allows privilege escalation to root level on Linux and BSD distributions using X.Org server, the open source implementation of the X Window System that offers the graphical environment.

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Three hours after the public announcement of the security gap, Daemon Security CEO Michael Shirk replied with one line that overwrote shadow files on the system. Hickey did one better and fit the entire local privilege escalation exploit in one line.

Apart from OpenBSD, other operating systems affected by the bug include Debian and UbuntuFedora and its downstream distro  Red Hat Enterprise Linux along with its community-supported counterpart CentOS.

Source: Trivial Bug in X.Org Gives Root Permission on Linux and BSD Systems