Vigil@nce - Linux kernel: information disclosure via NFS Write Delegation
February 2014 by Vigil@nce
This bulletin was written by Vigil@nce : http://vigilance.fr/offer
SYNTHESIS OF THE VULNERABILITY
A local attacker can edit a file on NFS with Write Delegation, in
order to obtain sensitive information coming from the Linux kernel
memory.
Impacted products: Linux
Severity: 1/4
Creation date: 20/02/2014
DESCRIPTION OF THE VULNERABILITY
The Write Delegation feature of NFSv4 allows the server to
delegate to the client the edition of files for which it is the
only user, in order to limit network exchanges.
The Linux kernel implements a NFS client. However, it does not
correctly manage its cache, and inserts bytes coming from the
kernel memory in the edited file.
A local attacker can therefore edit a file on NFS with Write
Delegation, in order to obtain sensitive information coming from
the Linux kernel memory.
ACCESS TO THE COMPLETE VIGIL@NCE BULLETIN
http://vigilance.fr/vulnerability/Linux-kernel-information-disclosure-via-NFS-Write-Delegation-14288