FreeBSD : xen-kernel -- GNTTABOP_swap_grant_ref operation misbehavior (80e846ff-27eb-11e5-a4a5-002590263bf5)

Medium Nessus Plugin ID 84706


The remote FreeBSD host is missing a security-related update.


The Xen Project reports :

With the introduction of version 2 grant table operations, a version check became necessary for most grant table related hypercalls. The GNTTABOP_swap_grant_ref call was lacking such a check. As a result, the subsequent code behaved as if version 2 was in use, when a guest issued this hypercall without a prior GNTTABOP_setup_table or GNTTABOP_set_version.

The effect is a possible NULL pointer dereferences. However, this cannot be exploited to elevate privileges of the attacking domain, as the maximum memory address that can be wrongly accessed this way is bounded to far below the start of hypervisor memory.

Malicious or buggy guest domain kernels can mount a denial of service attack which, if successful, can affect the whole system.


Update the affected package.

See Also

Plugin Details

Severity: Medium

ID: 84706

File Name: freebsd_pkg_80e846ff27eb11e5a4a5002590263bf5.nasl

Version: $Revision: 2.1 $

Type: local

Published: 2015/07/14

Modified: 2015/07/14

Dependencies: 12634

Risk Information

Risk Factor: Medium


Base Score: 4.9

Vector: CVSS2#AV:L/AC:L/Au:N/C:N/I:N/A:C

Vulnerability Information

CPE: p-cpe:/a:freebsd:freebsd:xen-kernel, cpe:/o:freebsd:freebsd

Required KB Items: Host/local_checks_enabled, Host/FreeBSD/release, Host/FreeBSD/pkg_info

Patch Publication Date: 2015/07/11

Vulnerability Publication Date: 2015/06/11

Reference Information

CVE: CVE-2015-4163