7.2 High
CVSS2
Attack Vector
LOCAL
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
COMPLETE
Integrity Impact
COMPLETE
Availability Impact
COMPLETE
AV:L/AC:L/Au:N/C:C/I:C/A:C
8.2 High
CVSS3
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
HIGH
User Interaction
NONE
Scope
CHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
8.2 High
AI Score
Confidence
High
0.001 Low
EPSS
Percentile
39.4%
AMD and Intel CPUs support hardware virtualization using specialized data structures that control various aspects of guest operation. These are the Virtual Machine Control Structure (VMCS) on Intel CPUs, and the Virtual Machine Control Block (VMCB) on AMD CPUs. Insufficient access controls allow root users, including those running in a jail, to change these data structures. Impact : An attacker with host root access (including to a jailed bhyve instance) can use this vulnerability to achieve kernel code execution.
#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from the FreeBSD VuXML database :
#
# Copyright 2003-2020 Jacques Vidrine and contributors
#
# Redistribution and use in source (VuXML) and 'compiled' forms (SGML,
# HTML, PDF, PostScript, RTF and so forth) with or without modification,
# are permitted provided that the following conditions are met:
# 1. Redistributions of source code (VuXML) must retain the above
# copyright notice, this list of conditions and the following
# disclaimer as the first lines of this file unmodified.
# 2. Redistributions in compiled form (transformed to other DTDs,
# published online in any format, converted to PDF, PostScript,
# RTF and other formats) must reproduce the above copyright
# notice, this list of conditions and the following disclaimer
# in the documentation and/or other materials provided with the
# distribution.
#
# THIS DOCUMENTATION IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
# THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
# PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS
# BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
# OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
# OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
# BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
# WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
# OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS DOCUMENTATION,
# EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#
include('compat.inc');
if (description)
{
script_id(140626);
script_version("1.4");
script_set_attribute(attribute:"plugin_modification_date", value:"2024/02/20");
script_cve_id("CVE-2020-24718");
script_xref(name:"FreeBSD", value:"SA-20:28.bhyve_vmcs");
script_name(english:"FreeBSD : FreeBSD -- bhyve privilege escalation via VMCS access (2c5b9cd7-f7e6-11ea-88f8-901b0ef719ab)");
script_set_attribute(attribute:"synopsis", value:
"The remote FreeBSD host is missing one or more security-related
updates.");
script_set_attribute(attribute:"description", value:
"AMD and Intel CPUs support hardware virtualization using specialized
data structures that control various aspects of guest operation. These
are the Virtual Machine Control Structure (VMCS) on Intel CPUs, and
the Virtual Machine Control Block (VMCB) on AMD CPUs. Insufficient
access controls allow root users, including those running in a jail,
to change these data structures. Impact : An attacker with host root
access (including to a jailed bhyve instance) can use this
vulnerability to achieve kernel code execution.");
# https://vuxml.freebsd.org/freebsd/2c5b9cd7-f7e6-11ea-88f8-901b0ef719ab.html
script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?b5cf029f");
script_set_attribute(attribute:"solution", value:
"Update the affected packages.");
script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:N/C:C/I:C/A:C");
script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C");
script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H");
script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
script_set_attribute(attribute:"cvss_score_source", value:"CVE-2020-24718");
script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
script_set_attribute(attribute:"exploit_available", value:"true");
script_set_attribute(attribute:"vuln_publication_date", value:"2020/09/15");
script_set_attribute(attribute:"patch_publication_date", value:"2020/09/16");
script_set_attribute(attribute:"plugin_publication_date", value:"2020/09/17");
script_set_attribute(attribute:"plugin_type", value:"local");
script_set_attribute(attribute:"cpe", value:"p-cpe:/a:freebsd:freebsd:FreeBSD");
script_set_attribute(attribute:"cpe", value:"cpe:/o:freebsd:freebsd");
script_set_attribute(attribute:"generated_plugin", value:"current");
script_end_attributes();
script_category(ACT_GATHER_INFO);
script_family(english:"FreeBSD Local Security Checks");
script_copyright(english:"This script is Copyright (C) 2020-2024 and is owned by Tenable, Inc. or an Affiliate thereof.");
script_dependencies("ssh_get_info.nasl");
script_require_keys("Host/local_checks_enabled", "Host/FreeBSD/release", "Host/FreeBSD/pkg_info", "Settings/ParanoidReport");
exit(0);
}
include("audit.inc");
include("freebsd_package.inc");
if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
if (!get_kb_item("Host/FreeBSD/release")) audit(AUDIT_OS_NOT, "FreeBSD");
if (!get_kb_item("Host/FreeBSD/pkg_info")) audit(AUDIT_PACKAGE_LIST_MISSING);
if (report_paranoia < 2) audit(AUDIT_PARANOID);
flag = 0;
if (pkg_test(save_report:TRUE, pkg:"FreeBSD>=12.1<12.1_10")) flag++;
if (pkg_test(save_report:TRUE, pkg:"FreeBSD>=11.4<11.4_4")) flag++;
if (pkg_test(save_report:TRUE, pkg:"FreeBSD>=11.3<11.3_14")) flag++;
if (flag)
{
if (report_verbosity > 0) security_hole(port:0, extra:pkg_report_get());
else security_hole(0);
exit(0);
}
else audit(AUDIT_HOST_NOT, "affected");
7.2 High
CVSS2
Attack Vector
LOCAL
Attack Complexity
LOW
Authentication
NONE
Confidentiality Impact
COMPLETE
Integrity Impact
COMPLETE
Availability Impact
COMPLETE
AV:L/AC:L/Au:N/C:C/I:C/A:C
8.2 High
CVSS3
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
HIGH
User Interaction
NONE
Scope
CHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
8.2 High
AI Score
Confidence
High
0.001 Low
EPSS
Percentile
39.4%