Ubuntu 18.04 LTS / 20.04 LTS : BusyBox vulnerability (USN-4531-1)

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-4531-1. 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(140736);
  script_version("1.4");
  script_set_attribute(attribute:"plugin_modification_date", value:"2023/10/20");

  script_cve_id("CVE-2018-1000500");
  script_xref(name:"USN", value:"4531-1");

  script_name(english:"Ubuntu 18.04 LTS / 20.04 LTS : BusyBox vulnerability (USN-4531-1)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Ubuntu host is missing a security update.");
  script_set_attribute(attribute:"description", value:
"The remote Ubuntu 18.04 LTS / 20.04 LTS host has packages installed that are affected by a vulnerability as referenced
in the USN-4531-1 advisory.

  - Busybox contains a Missing SSL certificate validation vulnerability in The busybox wget applet that can
    result in arbitrary code execution. This attack appear to be exploitable via Simply download any file over
    HTTPS using busybox wget https://compromised-domain.com/important-file. (CVE-2018-1000500)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version
number.");
  script_set_attribute(attribute:"see_also", value:"https://ubuntu.com/security/notices/USN-4531-1");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/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:H/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-2018-1000500");

  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:"2018/06/26");
  script_set_attribute(attribute:"patch_publication_date", value:"2020/09/22");
  script_set_attribute(attribute:"plugin_publication_date", value:"2020/09/22");

  script_set_attribute(attribute:"plugin_type", value:"local");
  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:20.04:-:lts");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:busybox");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:busybox-initramfs");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:busybox-static");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:busybox-syslogd");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:busybox-udeb");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:udhcpc");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:udhcpd");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Ubuntu Local Security Checks");

  script_copyright(english:"Ubuntu Security Notice (C) 2020-2023 Canonical, Inc. / NASL script (C) 2020-2023 and is owned by Tenable, Inc. or an Affiliate thereof.");

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

  exit(0);
}

include('debian_package.inc');

if ( ! get_kb_item('Host/local_checks_enabled') ) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
var os_release = get_kb_item('Host/Ubuntu/release');
if ( isnull(os_release) ) audit(AUDIT_OS_NOT, 'Ubuntu');
os_release = chomp(os_release);
if (! ('18.04' >< os_release || '20.04' >< os_release)) audit(AUDIT_OS_NOT, 'Ubuntu 18.04 / 20.04', 'Ubuntu ' + os_release);
if ( ! get_kb_item('Host/Debian/dpkg-l') ) audit(AUDIT_PACKAGE_LIST_MISSING);

var cpu = get_kb_item('Host/cpu');
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ('x86_64' >!< cpu && cpu !~ "^i[3-6]86$" && 's390' >!< cpu && 'aarch64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'Ubuntu', cpu);

var pkgs = [
    {'osver': '18.04', 'pkgname': 'busybox', 'pkgver': '1:1.27.2-2ubuntu3.3'},
    {'osver': '18.04', 'pkgname': 'busybox-initramfs', 'pkgver': '1:1.27.2-2ubuntu3.3'},
    {'osver': '18.04', 'pkgname': 'busybox-static', 'pkgver': '1:1.27.2-2ubuntu3.3'},
    {'osver': '18.04', 'pkgname': 'busybox-syslogd', 'pkgver': '1:1.27.2-2ubuntu3.3'},
    {'osver': '18.04', 'pkgname': 'busybox-udeb', 'pkgver': '1:1.27.2-2ubuntu3.3'},
    {'osver': '18.04', 'pkgname': 'udhcpc', 'pkgver': '1:1.27.2-2ubuntu3.3'},
    {'osver': '18.04', 'pkgname': 'udhcpd', 'pkgver': '1:1.27.2-2ubuntu3.3'},
    {'osver': '20.04', 'pkgname': 'busybox', 'pkgver': '1:1.30.1-4ubuntu6.2'},
    {'osver': '20.04', 'pkgname': 'busybox-initramfs', 'pkgver': '1:1.30.1-4ubuntu6.2'},
    {'osver': '20.04', 'pkgname': 'busybox-static', 'pkgver': '1:1.30.1-4ubuntu6.2'},
    {'osver': '20.04', 'pkgname': 'busybox-syslogd', 'pkgver': '1:1.30.1-4ubuntu6.2'},
    {'osver': '20.04', 'pkgname': 'busybox-udeb', 'pkgver': '1:1.30.1-4ubuntu6.2'},
    {'osver': '20.04', 'pkgname': 'udhcpc', 'pkgver': '1:1.30.1-4ubuntu6.2'},
    {'osver': '20.04', 'pkgname': 'udhcpd', 'pkgver': '1:1.30.1-4ubuntu6.2'}
];

var flag = 0;
foreach package_array ( pkgs ) {
  var osver = NULL;
  var pkgname = NULL;
  var pkgver = NULL;
  if (!empty_or_null(package_array['osver'])) osver = package_array['osver'];
  if (!empty_or_null(package_array['pkgname'])) pkgname = package_array['pkgname'];
  if (!empty_or_null(package_array['pkgver'])) pkgver = package_array['pkgver'];
  if (osver && pkgname && pkgver) {
    if (ubuntu_check(osver:osver, pkgname:pkgname, pkgver:pkgver)) flag++;
  }
}

if (flag)
{
  security_report_v4(
    port       : 0,
    severity   : SECURITY_WARNING,
    extra      : ubuntu_report_get()
  );
  exit(0);
}
else
{
  var tested = ubuntu_pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, 'busybox / busybox-initramfs / busybox-static / busybox-syslogd / etc');
}