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

Freely subscribe to our NEWSLETTER

Newsletter FR

Newsletter EN

Vulnérabilités

Unsubscribe

Vigil@nce: Linux kernel, privilege elevation via eCryptfs

October 2009 by Vigil@nce

A local attacker can create a hard link on an eCryptfs file
system, in order to generate a denial of service, or to execute
code.

 Severity: 2/4
 Consequences: administrator access/rights, denial of service of
computer
 Provenance: user shell
 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: 07/10/2009

IMPACTED PRODUCTS

 Linux kernel

DESCRIPTION OF THE VULNERABILITY

The Linux kernel supports the eCryptfs file system since version
2.6.19.

A file can have several hard links, which are different access
path to the same file.

When:
 a file is stored on an eCryptfs file system, and
 two hard links are available for this file, and
 the file is opened, and
 all links are removed, and
 a read() or write() is done on the previously opened file,
then, a NULL pointer is dereferenced in ecryptfs_read_update_atime()
(access time update). This error stops the kernel.

A local attacker can thus create a hard link on an eCryptfs file
system, in order to generate a denial of service.

An attacker can also use this vulnerability with
VIGILANCE-VUL-8953 (https://vigilance.fr/tree/1/8953)/VIGILANCE-VUL-8861
(https://vigilance.fr/tree/1/8861) in order to elevate his
privileges.

CHARACTERISTICS

 Identifiers: 527534, BID-36639, CVE-2009-2908, VIGILANCE-VUL-9075
 Url: http://vigilance.fr/vulnerability/Linux-kernel-privilege-elevation-via-eCryptfs-9075


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