Vigil@nce: netpbm, integer overflow via XPM
February 2010 by Vigil@nce
An attacker can create a malicious XPM image, and invite the
victim to convert it with xpmtoppm, in order to generate an
overflow leading to a denial of service and possibly to code
execution.
– Severity: 2/4
– Consequences: user access/rights, denial of service of service
– Provenance: document
– Means of attack: no proof of concept, no attack
– Ability of attacker: expert (4/4)
– Confidence: confirmed by the editor (5/5)
– Diffusion of the vulnerable configuration: high (3/3)
– Creation date: 10/02/2010
IMPACTED PRODUCTS
– Unix - plateform
DESCRIPTION OF THE VULNERABILITY
The netpbm suite converts images in PNM formats:
– PPM (Portable Pixmap) : color
– PGM (Portable Greymap) : greyscale
– PBM (Portable Bitmap) : black and white
The xpmtoppm tool converts an XPM image to the PPM format.
However, it does not check if the color index is superior to 127,
which corrupts the memory.
An attacker can therefore create a malicious XPM image, and invite
the victim to convert it with xpmtoppm, in order to generate an
overflow leading to a denial of service and possibly to code
execution.
CHARACTERISTICS
– Identifiers: BID-38164, CVE-2009-4274, VIGILANCE-VUL-9438
– Url: http://vigilance.fr/vulnerability/netpbm-integer-overflow-via-XPM-9438