vigil@nce : mktemp, no randomness in directories names
August 2008 by Vigil@nce
SYNTHESIS
An attacker can guess directories names created by mktemp, and
thus gain access to temporary files.
Gravity: 2/4
Consequences: data reading, data creation/edition
Provenance: LAN
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: 18/08/2008
Identifier: VIGILANCE-VUL-8034
IMPACTED PRODUCTS
– Debian Linux [confidential versions]
– Unix - plateform
DESCRIPTION
The "mktemp" tool is used to create temporary files from shell
scripts.
Several versions of "mktemp" do not generate random file names,
sometimes the name of the directory equals to the processus id, or
simply equals to this number + 1.
An attacker can therefore guess file names created by mktemp, and
thus gain access to temporary files.
CHARACTERISTICS
Identifiers: 495193, BID-30701, VIGILANCE-VUL-8034