rxvt-unicode 9.22, rxvt 2.7.10, mrxvt 0.5.4, and Eterm 0.9.7 allow (potentially remote) code execution because of improper handling of certain escape sequences (ESC G Q). A response is terminated by a newline.
Rxvt 2.7.10 is vulnerable to a denial of service attack by passing the value -2^31 inside a terminal escape code, which results in a non-invertible integer that eventually leads to a segfault due to an out of bounds read.
rxvt 2.6.4 opens a terminal window on :0 if the DISPLAY environment variable is not set, which might allow local users to hijack X11 connections. NOTE: it was later reported that rxvt-unicode, mrxvt, aterm, multi-aterm, and wterm are also affected. NOTE: realistic attack scenarios require that the victim enters a command on the wrong machine.
The menuBar feature in rxvt 2.7.8 allows attackers to modify menu options and execute arbitrary commands via a certain character escape sequence that inserts the commands into the menu.
The "screen dump" feature in rxvt 2.7.8 allows attackers to overwrite arbitrary files via a certain character escape sequence when it is echoed to a user's terminal, e.g. when the user views a file containing the malicious sequence.
The rxvt terminal emulator 2.7.8 and earlier 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.
Buffer overflow in tt_printf function of rxvt 2.6.2 allows local users to gain privileges via a long (1) -T or (2) -name argument.
rxvt, when compiled with the PRINT_PIPE option in various Linux operating systems including Linux Slackware 3.0 and RedHat 2.1, allows local users to gain root privileges by specifying a malicious program using the -print-pipe command line parameter.
xterm, Eterm, and rxvt allow an attacker to cause a denial of service by embedding certain escape characters which force the window to be resized.