Vigil@nce - GNOME vte: denial of service via insert-blank-characters
July 2011 by Vigil@nce
This bulletin was written by Vigil@nce : http://vigilance.fr/offer
SYNTHESIS OF THE VULNERABILITY
An attacker can invite the victim to display a text document with gnome-terminal (GNOME vte), in order to create a denial of service.
Creation date: 13/07/2011
Unix - plateform
DESCRIPTION OF THE VULNERABILITY
The gnome-terminal terminal uses the GNOME vte (Virtual Terminal Emulation) library (widget).
A terminal support ANSI sequences, which are used to alter the display:
^[ line; column H : move to the (line,column) screen coordinates
^[ num A : go up of num lines
^[ num @ : insert num spaces ("insert-blank-characters")
However, vte does not limit the number of spaces which can be inserted with "insert-blank-characters". The terminal thus consumes a lot a resources to display the spaces.
An attacker can therefore invite the victim to display a text document with gnome-terminal (GNOME vte), in order to create a denial of service.
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