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.

Buffer overflow in command.C for rxvt-unicode before 5.3 allows remote attackers to execute arbitrary code via a crafted file containing long escape sequences.

RXVT-Unicode 3.4 and 3.5 does not properly close file descriptors, which allows local users to access the terminals of other users and possibly gain privileges.