Updated rxvt packages are available which fix a number of vulnerabilities in the handling of escape sequences.
Rxvt is a color VT102 terminal emulator for the X Window System. A number of issues have been found in the escape sequence handling of Rxvt. These could be potentially exploited if an attacker can cause carefully crafted escape sequences to be displayed on a rxvt terminal being used by their victim. One of the features which most terminal emulators support is the ability for the shell to set the title of the window using an escape sequence. Certain xterm variants, including rxvt, also provide an escape sequence for reporting the current window title. This essentially takes the current title and places it directly on the command line. Since it is not possible to embed a carriage return into the window title itself, the attacker would have to convince the victim to hit enter for it to process the title as a command, although the attacker can perform a number of actions to increase the likelyhood of this happening. 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 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. Users of Rxvt are advised to upgrade to these errata packages which contain a patch to disable the title reporting functionality and patches to correct the other issues. Red Hat would like to thank H D Moore for bringing these issues to our attention.