Vulnerabilities > CVE-2017-7522 - NULL Pointer Dereference vulnerability in Openvpn

#
# (C) Tenable Network Security, Inc.
#
include("compat.inc");

if (description)
{
  script_id(125262);
  script_version("1.4");
  script_cvs_date("Date: 2019/10/30 13:24:47");

  script_cve_id(
    "CVE-2017-7508",
    "CVE-2017-7520",
    "CVE-2017-7521",
    "CVE-2017-7522"
  );
  script_bugtraq_id(99230);

  script_name(english:"OpenVPN 2.3.x < 2.3.17 & 2.4.x < 2.4.3 Multiple Denial of Service Vulnerabilites (Windows)");
  script_summary(english:"Checks the version of OpenVPN.");

  script_set_attribute(attribute:"synopsis", value:
"An application on the remote Windows host is affected by multiple vulnerabilities.");
  script_set_attribute(attribute:"description", value:
"According to its self-reported version number, the version of OpenVPN installed on the remote Windows host is 2.3.x 
prior to 2.3.17 or 2.4.x prior to 2.4.3. It is, therefore, affected by multiple denial of service (DoS) vulnerabilities 
due to invalid input validation. An unauthenticated, remote attacker can exploit this issue, by sending malformed input,
to cause the application to stop responding.");
  # https://community.openvpn.net/openvpn/wiki/VulnerabilitiesFixedInOpenVPN243
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?af9c7e6f");
  script_set_attribute(attribute:"solution", value:"Upgrade to OpenVPN 2.3.17 / 2.4.3 or later.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:H/Au:N/C:P/I:N/A:P");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/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-2017-7520");
  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  
  script_set_attribute(attribute:"vuln_publication_date", value:"2017/06/21");
  script_set_attribute(attribute:"patch_publication_date", value:"2017/06/22");
  script_set_attribute(attribute:"plugin_publication_date", value:"2019/05/17");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:openvpn:openvpn");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Windows");

  script_copyright(english:"This script is Copyright (C) 2019 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("openvpn_server_installed.nbin");
  script_require_keys("installed_sw/OpenVPN Server");
  exit(0);
}

include('vcf.inc');

app_info = vcf::get_app_info(app:'OpenVPN Server');

constraints = [
  {'min_version': '2.3.0', 'fixed_version': '2.3.17'},
  {'min_version': '2.4.0', 'fixed_version': '2.4.3'}
];
vcf::check_version_and_report(app_info:app_info, constraints:constraints, severity:SECURITY_WARNING);

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Amazon Linux AMI Security Advisory ALAS-2017-852.
#

include("compat.inc");

if (description)
{
  script_id(101064);
  script_version("3.9");
  script_cvs_date("Date: 2018/04/18 15:09:36");

  script_cve_id("CVE-2017-7508", "CVE-2017-7520", "CVE-2017-7521", "CVE-2017-7522");
  script_xref(name:"ALAS", value:"2017-852");

  script_name(english:"Amazon Linux AMI : openvpn (ALAS-2017-852)");
  script_summary(english:"Checks rpm output for the updated packages");

  script_set_attribute(
    attribute:"synopsis", 
    value:"The remote Amazon Linux AMI host is missing a security update."
  );
  script_set_attribute(
    attribute:"description", 
    value:
"OpenVPN versions before 2.4.3 and before 2.3.17 are vulnerable to
remote denial-of-service when receiving malformed IPv6 packet.
(CVE-2017-7508)

OpenVPN versions before 2.4.3 and before 2.3.17 are vulnerable to
denial-of-service by authenticated remote attacker via sending a
certificate with an embedded NULL character. (CVE-2017-7522)

OpenVPN versions before 2.4.3 and before 2.3.17 are vulnerable to
remote denial-of-service due to memory exhaustion caused by memory
leaks and double-free issue in extract_x509_extension().
(CVE-2017-7521)

OpenVPN versions before 2.4.3 and before 2.3.17 are vulnerable to
denial-of-service and/or possibly sensitive memory leak triggered by
man-in-the-middle attacker. (CVE-2017-7520)"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://alas.aws.amazon.com/ALAS-2017-852.html"
  );
  script_set_attribute(
    attribute:"solution", 
    value:"Run 'yum update openvpn' to update your system."
  );
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:P");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:openvpn");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:openvpn-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:openvpn-devel");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:amazon:linux");

  script_set_attribute(attribute:"patch_publication_date", value:"2017/06/27");
  script_set_attribute(attribute:"plugin_publication_date", value:"2017/06/28");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2017-2018 Tenable Network Security, Inc.");
  script_family(english:"Amazon Linux Local Security Checks");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/AmazonLinux/release", "Host/AmazonLinux/rpm-list");

  exit(0);
}


include("audit.inc");
include("global_settings.inc");
include("rpm.inc");


if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);

release = get_kb_item("Host/AmazonLinux/release");
if (isnull(release) || !strlen(release)) audit(AUDIT_OS_NOT, "Amazon Linux");
os_ver = pregmatch(pattern: "^AL(A|\d)", string:release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, "Amazon Linux");
os_ver = os_ver[1];
if (os_ver != "A")
{
  if (os_ver == 'A') os_ver = 'AMI';
  audit(AUDIT_OS_NOT, "Amazon Linux AMI", "Amazon Linux " + os_ver);
}

if (!get_kb_item("Host/AmazonLinux/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING);


flag = 0;
if (rpm_check(release:"ALA", reference:"openvpn-2.4.3-1.19.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"openvpn-debuginfo-2.4.3-1.19.amzn1")) flag++;
if (rpm_check(release:"ALA", reference:"openvpn-devel-2.4.3-1.19.amzn1")) flag++;

if (flag)
{
  if (report_verbosity > 0) security_warning(port:0, extra:rpm_report_get());
  else security_warning(0);
  exit(0);
}
else
{
  tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, "openvpn / openvpn-debuginfo / openvpn-devel");
}

#
# (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.
#

include("compat.inc");

if (description)
{
  script_id(100976);
  script_version("3.9");
  script_cvs_date("Date: 2018/11/10 11:49:46");

  script_cve_id("CVE-2017-7508", "CVE-2017-7512", "CVE-2017-7520", "CVE-2017-7521", "CVE-2017-7522");

  script_name(english:"FreeBSD : OpenVPN -- several vulnerabilities (9f65d382-56a4-11e7-83e3-080027ef73ec)");
  script_summary(english:"Checks for updated packages in pkg_info output");

  script_set_attribute(
    attribute:"synopsis", 
    value:
"The remote FreeBSD host is missing one or more security-related
updates."
  );
  script_set_attribute(
    attribute:"description", 
    value:
"Samuli Seppanen reports :

In May/June 2017 Guido Vranken threw a fuzzer at OpenVPN 2.4.2. In the
process he found several vulnerabilities and reported them to the
OpenVPN project. [...] The first releases to have these fixes are
OpenVPN 2.4.3 and 2.3.17.

This is a list of fixed important vulnerabilities :

- Remotely-triggerable ASSERT() on malformed IPv6 packet

- Pre-authentication remote crash/information disclosure for clients

- Potential double-free in --x509-alt-username

- Remote-triggerable memory leaks

- Post-authentication remote DoS when using the --x509-track option

- NULL pointer dereference in establish_http_proxy_passthru()"
  );
  # https://community.openvpn.net/openvpn/wiki/VulnerabilitiesFixedInOpenVPN243
  script_set_attribute(
    attribute:"see_also",
    value:"http://www.nessus.org/u?af9c7e6f"
  );
  # https://vuxml.freebsd.org/freebsd/9f65d382-56a4-11e7-83e3-080027ef73ec.html
  script_set_attribute(
    attribute:"see_also",
    value:"http://www.nessus.org/u?20eadacf"
  );
  script_set_attribute(attribute:"solution", value:"Update the affected packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/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:openvpn");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:freebsd:freebsd:openvpn-mbedtls");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:freebsd:freebsd:openvpn-polarssl");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:freebsd:freebsd");

  script_set_attribute(attribute:"vuln_publication_date", value:"2017/05/19");
  script_set_attribute(attribute:"patch_publication_date", value:"2017/06/21");
  script_set_attribute(attribute:"plugin_publication_date", value:"2017/06/22");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2017-2018 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:"openvpn<2.3.17")) flag++;
if (pkg_test(save_report:TRUE, pkg:"openvpn>=2.4.0<2.4.3")) flag++;
if (pkg_test(save_report:TRUE, pkg:"openvpn-mbedtls<2.4.3")) flag++;
if (pkg_test(save_report:TRUE, pkg:"openvpn-polarssl<2.3.17")) 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");

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were  
# extracted from Slackware Security Advisory 2017-172-01. The text 
# itself is copyright (C) Slackware Linux, Inc.
#

include("compat.inc");

if (description)
{
  script_id(100964);
  script_version("$Revision: 3.5 $");
  script_cvs_date("$Date: 2018/01/26 17:50:31 $");

  script_cve_id("CVE-2017-7508", "CVE-2017-7512", "CVE-2017-7520", "CVE-2017-7521", "CVE-2017-7522");
  script_xref(name:"SSA", value:"2017-172-01");

  script_name(english:"Slackware 13.0 / 13.1 / 13.37 / 14.0 / 14.1 / 14.2 / current : openvpn (SSA:2017-172-01)");
  script_summary(english:"Checks for updated package in /var/log/packages");

  script_set_attribute(
    attribute:"synopsis", 
    value:"The remote Slackware host is missing a security update."
  );
  script_set_attribute(
    attribute:"description", 
    value:
"New openvpn packages are available for Slackware 13.0, 13.1, 13.37,
14.0, 14.1, 14.2, and -current to fix security issues."
  );
  # http://www.slackware.com/security/viewer.php?l=slackware-security&y=2017&m=slackware-security.569890
  script_set_attribute(
    attribute:"see_also",
    value:"http://www.nessus.org/u?7420c6e1"
  );
  script_set_attribute(
    attribute:"solution", 
    value:"Update the affected openvpn package."
  );
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:slackware:slackware_linux:openvpn");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:slackware:slackware_linux");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:slackware:slackware_linux:13.0");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:slackware:slackware_linux:13.1");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:slackware:slackware_linux:13.37");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:slackware:slackware_linux:14.0");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:slackware:slackware_linux:14.1");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:slackware:slackware_linux:14.2");

  script_set_attribute(attribute:"patch_publication_date", value:"2017/06/21");
  script_set_attribute(attribute:"plugin_publication_date", value:"2017/06/22");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2017-2018 Tenable Network Security, Inc.");
  script_family(english:"Slackware Local Security Checks");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/Slackware/release", "Host/Slackware/packages");

  exit(0);
}


include("audit.inc");
include("global_settings.inc");
include("slackware.inc");


if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
if (!get_kb_item("Host/Slackware/release")) audit(AUDIT_OS_NOT, "Slackware");
if (!get_kb_item("Host/Slackware/packages")) audit(AUDIT_PACKAGE_LIST_MISSING);


cpu = get_kb_item("Host/cpu");
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ("x86_64" >!< cpu && cpu !~ "^i[3-6]86$") audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, "Slackware", cpu);


flag = 0;
if (slackware_check(osver:"13.0", pkgname:"openvpn", pkgver:"2.3.17", pkgarch:"i486", pkgnum:"1_slack13.0")) flag++;
if (slackware_check(osver:"13.0", arch:"x86_64", pkgname:"openvpn", pkgver:"2.3.17", pkgarch:"x86_64", pkgnum:"1_slack13.0")) flag++;

if (slackware_check(osver:"13.1", pkgname:"openvpn", pkgver:"2.3.17", pkgarch:"i486", pkgnum:"1_slack13.1")) flag++;
if (slackware_check(osver:"13.1", arch:"x86_64", pkgname:"openvpn", pkgver:"2.3.17", pkgarch:"x86_64", pkgnum:"1_slack13.1")) flag++;

if (slackware_check(osver:"13.37", pkgname:"openvpn", pkgver:"2.3.17", pkgarch:"i486", pkgnum:"1_slack13.37")) flag++;
if (slackware_check(osver:"13.37", arch:"x86_64", pkgname:"openvpn", pkgver:"2.3.17", pkgarch:"x86_64", pkgnum:"1_slack13.37")) flag++;

if (slackware_check(osver:"14.0", pkgname:"openvpn", pkgver:"2.3.17", pkgarch:"i486", pkgnum:"1_slack14.0")) flag++;
if (slackware_check(osver:"14.0", arch:"x86_64", pkgname:"openvpn", pkgver:"2.3.17", pkgarch:"x86_64", pkgnum:"1_slack14.0")) flag++;

if (slackware_check(osver:"14.1", pkgname:"openvpn", pkgver:"2.3.17", pkgarch:"i486", pkgnum:"1_slack14.1")) flag++;
if (slackware_check(osver:"14.1", arch:"x86_64", pkgname:"openvpn", pkgver:"2.3.17", pkgarch:"x86_64", pkgnum:"1_slack14.1")) flag++;

if (slackware_check(osver:"14.2", pkgname:"openvpn", pkgver:"2.3.17", pkgarch:"i586", pkgnum:"1_slack14.2")) flag++;
if (slackware_check(osver:"14.2", arch:"x86_64", pkgname:"openvpn", pkgver:"2.3.17", pkgarch:"x86_64", pkgnum:"1_slack14.2")) flag++;

if (slackware_check(osver:"current", pkgname:"openvpn", pkgver:"2.4.3", pkgarch:"i586", pkgnum:"1")) flag++;
if (slackware_check(osver:"current", arch:"x86_64", pkgname:"openvpn", pkgver:"2.4.3", pkgarch:"x86_64", pkgnum:"1")) flag++;


if (flag)
{
  if (report_verbosity > 0) security_hole(port:0, extra:slackware_report_get());
  else security_hole(0);
  exit(0);
}
else audit(AUDIT_HOST_NOT, "affected");