X.Org and XFree86, including libX11, xdm, xf86dga, xinit, xload, xtrans, and xterm, does not check the return values for setuid and seteuid calls when attempting to drop privileges, which might allow local users to gain privileges by causing those calls to fail, such as by exceeding a ulimit.

Buffer overflow in dxterm in Ultrix 4.5 allows local users to execute arbitrary code via a long -setup parameter.

The uxterm terminal emulator allows attackers to modify the window title via a certain character escape sequence and then insert it back to the command line in the user's terminal, e.g. when the user views a file containing the malicious sequence, which could allow the attacker to execute arbitrary commands.