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SYNTHESIS OF THE VULNERABILITY
A NFS client can create special files via mknod().
Gravity: 1/4
Consequences: privileged access/rights
Provenance: user account
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: 23/03/2009

IMPACTED PRODUCTS

– Linux kernel

DESCRIPTION OF THE VULNERABILITY

The mknod() system call is used to create special files. The user
must have the CAP_MKNOD capability to be allowed to use it.

The CAP_NFSD_SET variable of linux/capability.h defines
capabilities left to the client by the nfsd daemon. However,
CAP_NFSD_SET does not suppress the CAP_MKNOD capability.

A NFS client can therefore create special files via mknod().

CHARACTERISTICS

Identifiers: BID-34205, VIGILANCE-VUL-8553

http://vigilance.fr/vulnerability/Linux-kernel-privilege-elevation-via-nfsd-8553