Lucene search

K
nessusThis script is Copyright (C) 2023 and is owned by Tenable, Inc. or an Affiliate thereof.FREEBSD_PKG_AB43756147C011EE8E38002590C1F29C.NASL
HistoryAug 31, 2023 - 12:00 a.m.

FreeBSD : FreeBSD -- bhyve privileged guest escape via fwctl (ab437561-47c0-11ee-8e38-002590c1f29c)

2023-08-3100:00:00
This script is Copyright (C) 2023 and is owned by Tenable, Inc. or an Affiliate thereof.
www.tenable.com
3
freebsd
fwctl
buffer overflow
vulnerability
bhyve
privilege escalation
cve-2023-3494
security advisory

8.8 High

CVSS3

Attack Vector

LOCAL

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

CHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

0.0004 Low

EPSS

Percentile

5.1%

The version of FreeBSD installed on the remote host is prior to tested version. It is, therefore, affected by a vulnerability as referenced in the ab437561-47c0-11ee-8e38-002590c1f29c advisory.

  • The fwctl driver implements a state machine which is executed when a bhyve guest accesses certain x86 I/O ports. The interface lets the guest copy a string into a buffer resident in the bhyve process’ memory. A bug in the state machine implementation can result in a buffer overflowing when copying this string.
    Malicious, privileged software running in a guest VM can exploit the buffer overflow to achieve code execution on the host in the bhyve userspace process, which typically runs as root, mitigated by the capabilities assigned through the Capsicum sandbox available to the bhyve process. (CVE-2023-3494)

Note that Nessus has not tested for this issue but has instead relied only on the application’s self-reported version number.

#%NASL_MIN_LEVEL 80900
#
# (C) Tenable, Inc.
#
# @NOAGENT@
#
# The descriptive text and package checks in this plugin were
# extracted from the FreeBSD VuXML database :
#
# Copyright 2003-2021 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(180346);
  script_version("1.0");
  script_set_attribute(attribute:"plugin_modification_date", value:"2023/08/31");

  script_cve_id("CVE-2023-3494");

  script_name(english:"FreeBSD : FreeBSD -- bhyve privileged guest escape via fwctl (ab437561-47c0-11ee-8e38-002590c1f29c)");

  script_set_attribute(attribute:"synopsis", value:
"The remote FreeBSD host is missing one or more security-related updates.");
  script_set_attribute(attribute:"description", value:
"The version of FreeBSD installed on the remote host is prior to tested version. It is, therefore, affected by a
vulnerability as referenced in the ab437561-47c0-11ee-8e38-002590c1f29c advisory.

  - The fwctl driver implements a state machine which is executed when a bhyve guest accesses certain x86 I/O
    ports. The interface lets the guest copy a string into a buffer resident in the bhyve process' memory. A
    bug in the state machine implementation can result in a buffer overflowing when copying this string.
    Malicious, privileged software running in a guest VM can exploit the buffer overflow to achieve code
    execution on the host in the bhyve userspace process, which typically runs as root, mitigated by the
    capabilities assigned through the Capsicum sandbox available to the bhyve process. (CVE-2023-3494)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version
number.");
  # https://vuxml.freebsd.org/freebsd/ab437561-47c0-11ee-8e38-002590c1f29c.html
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?faebd93f");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:S/C:C/I:C/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2023-3494");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");

  script_set_attribute(attribute:"vuln_publication_date", value:"2023/08/01");
  script_set_attribute(attribute:"patch_publication_date", value:"2023/08/31");
  script_set_attribute(attribute:"plugin_publication_date", value:"2023/08/31");

  script_set_attribute(attribute:"plugin_type", value:"local");
  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) 2023 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");

  exit(0);
}


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);

var flag = 0;

var packages = [
    'FreeBSD>=13.1<13.1_9',
    'FreeBSD>=13.2<13.2_2'
];

foreach var package( packages ) {
    if (pkg_test(save_report:TRUE, pkg: package)) flag++;
}

if (flag)
{
  security_report_v4(
    port       : 0,
    severity   : SECURITY_WARNING,
    extra      : pkg_report_get()
  );
  exit(0);
}
else audit(AUDIT_HOST_NOT, "affected");
VendorProductVersionCPE
freebsdfreebsdcpe:/o:freebsd:freebsd

8.8 High

CVSS3

Attack Vector

LOCAL

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

CHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

0.0004 Low

EPSS

Percentile

5.1%

Related for FREEBSD_PKG_AB43756147C011EE8E38002590C1F29C.NASL