FreeBSD : xen-tools -- QEMU: Banked access to VGA memory (VBE) uses inconsistent bounds checks (e6ce6f50-4212-11e6-942d-bc5ff45d0f28)

2016-07-05T00:00:00
ID FREEBSD_PKG_E6CE6F50421211E6942DBC5FF45D0F28.NASL
Type nessus
Reporter Tenable
Modified 2018-11-10T00:00:00

Description

The Xen Project reports :

Qemu VGA module allows banked access to video memory using the window at 0xa00000 and it supports different access modes with different address calculations.

Qemu VGA module allows guest to edit certain registers in 'vbe' and 'vga' modes.

A privileged guest user could use CVE-2016-3710 to exceed the bank address window and write beyond the said memory area, potentially leading to arbitrary code execution with privileges of the Qemu process. If the system is not using stubdomains, this will be in domain 0.

A privileged guest user could use CVE-2016-3712 to cause potential integer overflow or OOB read access issues in Qemu, resulting in a DoS of the guest itself. More dangerous effect, such as data leakage or code execution, are not known but cannot be ruled out.

                                        
                                            #
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were  
# extracted from the FreeBSD VuXML database :
#
# Copyright 2003-2018 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.
#

if (NASL_LEVEL < 3000) exit(0);

include("compat.inc");

if (description)
{
  script_id(91938);
  script_version("2.3");
  script_cvs_date("Date: 2018/11/10 11:49:46");

  script_cve_id("CVE-2016-3710", "CVE-2016-3712");

  script_name(english:"FreeBSD : xen-tools -- QEMU: Banked access to VGA memory (VBE) uses inconsistent bounds checks (e6ce6f50-4212-11e6-942d-bc5ff45d0f28)");
  script_summary(english:"Checks for updated package in pkg_info output");

  script_set_attribute(
    attribute:"synopsis", 
    value:"The remote FreeBSD host is missing a security-related update."
  );
  script_set_attribute(
    attribute:"description", 
    value:
"The Xen Project reports :

Qemu VGA module allows banked access to video memory using the window
at 0xa00000 and it supports different access modes with different
address calculations.

Qemu VGA module allows guest to edit certain registers in 'vbe' and
'vga' modes.

A privileged guest user could use CVE-2016-3710 to exceed the bank
address window and write beyond the said memory area, potentially
leading to arbitrary code execution with privileges of the Qemu
process. If the system is not using stubdomains, this will be in
domain 0.

A privileged guest user could use CVE-2016-3712 to cause potential
integer overflow or OOB read access issues in Qemu, resulting in a DoS
of the guest itself. More dangerous effect, such as data leakage or
code execution, are not known but cannot be ruled out."
  );
  script_set_attribute(
    attribute:"see_also",
    value:"http://xenbits.xen.org/xsa/advisory-179.html"
  );
  # https://vuxml.freebsd.org/freebsd/e6ce6f50-4212-11e6-942d-bc5ff45d0f28.html
  script_set_attribute(
    attribute:"see_also",
    value:"http://www.nessus.org/u?6d5cb59f"
  );
  script_set_attribute(attribute:"solution", value:"Update the affected package.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:N/C:C/I:C/A: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_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:freebsd:freebsd:xen-tools");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:freebsd:freebsd");

  script_set_attribute(attribute:"vuln_publication_date", value:"2016/05/09");
  script_set_attribute(attribute:"patch_publication_date", value:"2016/07/04");
  script_set_attribute(attribute:"plugin_publication_date", value:"2016/07/05");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2016-2018 and is owned by Tenable, Inc. or an Affiliate thereof.");
  script_family(english:"FreeBSD Local Security Checks");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/FreeBSD/release", "Host/FreeBSD/pkg_info");

  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);


flag = 0;

if (pkg_test(save_report:TRUE, pkg:"xen-tools<4.7.0_2")) 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");