Vigil@nce: Ghostscript, denial of service via JBIG2
October 2009 by Vigil@nce
An attacker can create a PDF file containing a malicious JBIG2
image, in order to stop the Ghostscript application.
Severity: 1/4
Consequences: denial of service of client
Provenance: document
Means of attack: 1 attack
Ability of attacker: technician (2/4)
Confidence: confirmed by the editor (5/5)
Diffusion of the vulnerable configuration: high (3/3)
Creation date: 27/10/2009
IMPACTED PRODUCTS
– Fedora
– Unix - plateform
DESCRIPTION OF THE VULNERABILITY
A PDF document is composed of "stream" objects. These objects can
contain pages, images, fonts, etc.
An image can be compressed with the JBIG2 (Joint Bi-level Image
experts Group) compression algorithm.
However, Ghostscript does not correctly checks data of a JBIG2
image when uncompressing it, and a NULL pointer is dererefenced.
An attacker can therefore create a PDF file containing a malicious
JBIG2 image, in order to stop the Ghostscript application.
CHARACTERISTICS
Identifiers: 503785, FEDORA-2009-8270, VIGILANCE-VUL-9125
http://vigilance.fr/vulnerability/Ghostscript-denial-of-service-via-JBIG2-9125