Vigil@nce - Xen: denial of service via XENMEM_exchange
December 2015 by Vigil@nce
This bulletin was written by Vigil@nce : http://vigilance.fr/offer
SYNTHESIS OF THE VULNERABILITY
An attacker, who is administrator in a guest system, can use the
XENMEM_exchange hypercall on Xen, in order to trigger a denial of
service on the host system.
Impacted products: XenServer, Fedora, Xen.
Severity: 1/4.
Creation date: 08/12/2015.
DESCRIPTION OF THE VULNERABILITY
The Xen product can exchange memory pages with the XENMEM_exchange
hypercall. However, an attacker can trigger two vulnerabilities in
this hypercall.
An attacker can use XENMEM_exchange when the domain is stopped, in
order to trigger a denial of service on the host. [severity:1/4;
CVE-2015-8339]
An attacker can generate a fatal error in a lock management by
XENMEM_exchange, in order to trigger a denial of service.
[severity:1/4; CVE-2015-8340]
An attacker, who is administrator in a guest system, can therefore
use the XENMEM_exchange hypercall on Xen, in order to trigger a
denial of service on the host system.
ACCESS TO THE COMPLETE VIGIL@NCE BULLETIN
http://vigilance.fr/vulnerability/Xen-denial-of-service-via-XENMEM-exchange-18461