Vulnerabilities > CVE-2018-20023 - Improper Initialization vulnerability in multiple products

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-3877-1. The text 
# itself is copyright (C) Canonical, Inc. See 
# <http://www.ubuntu.com/usn/>. Ubuntu(R) is a registered 
# trademark of Canonical, Inc.
#

include("compat.inc");

if (description)
{
  script_id(121541);
  script_version("1.3");
  script_set_attribute(attribute:"plugin_modification_date", value:"2020/02/20");

  script_cve_id("CVE-2018-15126", "CVE-2018-15127", "CVE-2018-20019", "CVE-2018-20020", "CVE-2018-20021", "CVE-2018-20022", "CVE-2018-20023", "CVE-2018-20024", "CVE-2018-20748", "CVE-2018-20749", "CVE-2018-20750", "CVE-2018-6307");
  script_xref(name:"USN", value:"3877-1");

  script_name(english:"Ubuntu 14.04 LTS / 16.04 LTS / 18.04 LTS / 18.10 : libvncserver vulnerabilities (USN-3877-1)");
  script_summary(english:"Checks dpkg output for updated packages.");

  script_set_attribute(
    attribute:"synopsis", 
    value:
"The remote Ubuntu host is missing one or more security-related
patches."
  );
  script_set_attribute(
    attribute:"description", 
    value:
"It was discovered that LibVNCServer incorrectly handled certain
operations. A remote attacker able to connect to applications using
LibVNCServer could possibly use this issue to obtain sensitive
information, cause a denial of service, or execute arbitrary code.

Note that Tenable Network Security has extracted the preceding
description block directly from the Ubuntu security advisory. Tenable
has attempted to automatically clean and format it as much as possible
without introducing additional issues."
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://usn.ubuntu.com/3877-1/"
  );
  script_set_attribute(
    attribute:"solution", 
    value:
"Update the affected libvncclient1, libvncserver0 and / or
libvncserver1 packages."
  );
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:P/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:L/PR:N/UI:N/S:U/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-2018-20750");
  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libvncclient1");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libvncserver0");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libvncserver1");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:14.04");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:16.04");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:18.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:18.10");

  script_set_attribute(attribute:"vuln_publication_date", value:"2018/12/19");
  script_set_attribute(attribute:"patch_publication_date", value:"2019/01/31");
  script_set_attribute(attribute:"plugin_publication_date", value:"2019/02/01");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"Ubuntu Security Notice (C) 2019-2020 Canonical, Inc. / NASL script (C) 2019-2020 and is owned by Tenable, Inc. or an Affiliate thereof.");
  script_family(english:"Ubuntu Local Security Checks");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/cpu", "Host/Ubuntu", "Host/Ubuntu/release", "Host/Debian/dpkg-l");

  exit(0);
}


include("audit.inc");
include("ubuntu.inc");
include("misc_func.inc");

if ( ! get_kb_item("Host/local_checks_enabled") ) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
release = get_kb_item("Host/Ubuntu/release");
if ( isnull(release) ) audit(AUDIT_OS_NOT, "Ubuntu");
release = chomp(release);
if (! preg(pattern:"^(14\.04|16\.04|18\.04|18\.10)$", string:release)) audit(AUDIT_OS_NOT, "Ubuntu 14.04 / 16.04 / 18.04 / 18.10", "Ubuntu " + release);
if ( ! get_kb_item("Host/Debian/dpkg-l") ) 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, "Ubuntu", cpu);

flag = 0;

if (ubuntu_check(osver:"14.04", pkgname:"libvncserver0", pkgver:"0.9.9+dfsg-1ubuntu1.4")) flag++;
if (ubuntu_check(osver:"16.04", pkgname:"libvncclient1", pkgver:"0.9.10+dfsg-3ubuntu0.16.04.3")) flag++;
if (ubuntu_check(osver:"16.04", pkgname:"libvncserver1", pkgver:"0.9.10+dfsg-3ubuntu0.16.04.3")) flag++;
if (ubuntu_check(osver:"18.04", pkgname:"libvncclient1", pkgver:"0.9.11+dfsg-1ubuntu1.1")) flag++;
if (ubuntu_check(osver:"18.04", pkgname:"libvncserver1", pkgver:"0.9.11+dfsg-1ubuntu1.1")) flag++;
if (ubuntu_check(osver:"18.10", pkgname:"libvncclient1", pkgver:"0.9.11+dfsg-1.1ubuntu0.1")) flag++;
if (ubuntu_check(osver:"18.10", pkgname:"libvncserver1", pkgver:"0.9.11+dfsg-1.1ubuntu0.1")) flag++;

if (flag)
{
  security_report_v4(
    port       : 0,
    severity   : SECURITY_HOLE,
    extra      : ubuntu_report_get()
  );
  exit(0);
}
else
{
  tested = ubuntu_pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, "libvncclient1 / libvncserver0 / libvncserver1");
}

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were  
# extracted from Debian Security Advisory DSA-4383. The text 
# itself is copyright (C) Software in the Public Interest, Inc.
#

include("compat.inc");

if (description)
{
  script_id(121561);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2020/02/20");

  script_cve_id("CVE-2018-15126", "CVE-2018-15127", "CVE-2018-20019", "CVE-2018-20020", "CVE-2018-20021", "CVE-2018-20022", "CVE-2018-20023", "CVE-2018-20024", "CVE-2018-6307");
  script_xref(name:"DSA", value:"4383");

  script_name(english:"Debian DSA-4383-1 : libvncserver - security update");
  script_summary(english:"Checks dpkg output for the updated package");

  script_set_attribute(
    attribute:"synopsis", 
    value:"The remote Debian host is missing a security-related update."
  );
  script_set_attribute(
    attribute:"description", 
    value:
"Pavel Cheremushkin discovered several vulnerabilities in libvncserver,
a library to implement VNC server/client functionalities, which might
result in the execution of arbitrary code, denial of service or
information disclosure."
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=916941"
  );
  # https://security-tracker.debian.org/tracker/source-package/libvncserver
  script_set_attribute(
    attribute:"see_also",
    value:"http://www.nessus.org/u?b930abb4"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://packages.debian.org/source/stretch/libvncserver"
  );
  script_set_attribute(
    attribute:"see_also",
    value:"https://www.debian.org/security/2019/dsa-4383"
  );
  script_set_attribute(
    attribute:"solution", 
    value:
"Upgrade the libvncserver packages.

For the stable distribution (stretch), these problems have been fixed
in version 0.9.11+dfsg-1.3~deb9u1."
  );
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:P/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:L/PR:N/UI:N/S:U/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-2018-20020");
  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:debian:debian_linux:libvncserver");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:debian:debian_linux:9.0");

  script_set_attribute(attribute:"vuln_publication_date", value:"2018/12/19");
  script_set_attribute(attribute:"patch_publication_date", value:"2019/02/03");
  script_set_attribute(attribute:"plugin_publication_date", value:"2019/02/04");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_copyright(english:"This script is Copyright (C) 2019-2020 and is owned by Tenable, Inc. or an Affiliate thereof.");
  script_family(english:"Debian Local Security Checks");

  script_dependencies("ssh_get_info.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/Debian/release", "Host/Debian/dpkg-l");

  exit(0);
}


include("audit.inc");
include("debian_package.inc");


if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
if (!get_kb_item("Host/Debian/release")) audit(AUDIT_OS_NOT, "Debian");
if (!get_kb_item("Host/Debian/dpkg-l")) audit(AUDIT_PACKAGE_LIST_MISSING);


flag = 0;
if (deb_check(release:"9.0", prefix:"libvncclient1", reference:"0.9.11+dfsg-1.3~deb9u1")) flag++;
if (deb_check(release:"9.0", prefix:"libvncclient1-dbg", reference:"0.9.11+dfsg-1.3~deb9u1")) flag++;
if (deb_check(release:"9.0", prefix:"libvncserver-config", reference:"0.9.11+dfsg-1.3~deb9u1")) flag++;
if (deb_check(release:"9.0", prefix:"libvncserver-dev", reference:"0.9.11+dfsg-1.3~deb9u1")) flag++;
if (deb_check(release:"9.0", prefix:"libvncserver1", reference:"0.9.11+dfsg-1.3~deb9u1")) flag++;
if (deb_check(release:"9.0", prefix:"libvncserver1-dbg", reference:"0.9.11+dfsg-1.3~deb9u1")) flag++;

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