Rechercher
Contactez-nous Suivez-nous sur Twitter En francais English Language
 

Freely subscribe to our NEWSLETTER

Newsletter FR

Newsletter EN

Vulnérabilités

Unsubscribe

Vigil@nce: FreeBSD, privilege elevation on amd64

September 2008 by Vigil@nce

A local attacker can obtain root privileges on a FreeBSD/amd64
system.

 Gravity: 2/4
 Consequences: administrator access/rights
 Provenance: user shell
 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: 04/09/2008
 Identifier: VIGILANCE-VUL-8087

IMPACTED PRODUCTS

 FreeBSD [confidential versions]

DESCRIPTION

The FreeBSD/amd64 system uses the GS segment to store:
 in user mode : information on threads
 in kernel mode : information on processes

The SwapGS assembler instruction swaps GS and the "KernelGSbase"
MSR (Model Specific Register). This instruction is called for each
mode change.

However, if a GPF (General Protection Fault) occurs when returning
from an interrupt, trap or system call, SwapGS is called twice.
Kernel GS data can thus be altered by the user.

A local attacker can therefore execute code with kernel privileges.

CHARACTERISTICS

 Identifiers: BID-31003, CVE-2008-3890, FreeBSD-SA-08:07.amd64,
VIGILANCE-VUL-8087
 Url: https://vigilance.aql.fr/tree/1/8087


See previous articles

    

See next articles


Your podcast Here

New, you can have your Podcast here. Contact us for more information ask:
Marc Brami
Phone: +33 1 40 92 05 55
Mail: ipsimp@free.fr

All new podcasts