Ubuntu 18.04 LTS : Samba vulnerabilities (USN-5174-1)

#%NASL_MIN_LEVEL 70300
##
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-5174-1. The text
# itself is copyright (C) Canonical, Inc. See
# <https://ubuntu.com/security/notices>. Ubuntu(R) is a registered
# trademark of Canonical, Inc.
##

include('deprecated_nasl_level.inc');
include('compat.inc');

if (description)
{
  script_id(155936);
  script_version("1.7");
  script_set_attribute(attribute:"plugin_modification_date", value:"2023/10/16");

  script_cve_id(
    "CVE-2016-2124",
    "CVE-2020-25717",
    "CVE-2020-25722",
    "CVE-2021-3671"
  );
  script_xref(name:"USN", value:"5174-1");

  script_name(english:"Ubuntu 18.04 LTS : Samba vulnerabilities (USN-5174-1)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Ubuntu host is missing one or more security updates.");
  script_set_attribute(attribute:"description", value:
"The remote Ubuntu 18.04 LTS host has packages installed that are affected by multiple vulnerabilities as referenced in
the USN-5174-1 advisory.

  - A null pointer de-reference was found in the way samba kerberos server handled missing sname in TGS-REQ
    (Ticket Granting Server - Request). An authenticated user could use this flaw to crash the samba server.
    (CVE-2021-3671)

  - A flaw was found in the way samba implemented SMB1 authentication. An attacker could use this flaw to
    retrieve the plaintext password sent over the wire even if Kerberos authentication was required.
    (CVE-2016-2124)

  - A flaw was found in the way Samba maps domain users to local users. An authenticated attacker could use
    this flaw to cause possible privilege escalation. (CVE-2020-25717)

  - Multiple flaws were found in the way samba AD DC implemented access and conformance checking of stored
    data. An attacker could use this flaw to cause total domain compromise. (CVE-2020-25722)

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-5174-1");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:S/C:C/I:C/A:N");
  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:L/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-2020-25717");
  script_set_attribute(attribute:"cvss3_score_source", value:"CVE-2020-25722");

  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:"2021/10/12");
  script_set_attribute(attribute:"patch_publication_date", value:"2021/12/06");
  script_set_attribute(attribute:"plugin_publication_date", value:"2021/12/08");

  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:"p-cpe:/a:canonical:ubuntu_linux:ctdb");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libnss-winbind");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libpam-winbind");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libparse-pidl-perl");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libsmbclient");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libsmbclient-dev");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libwbclient-dev");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libwbclient0");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:python-samba");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:registry-tools");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:samba");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:samba-common");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:samba-common-bin");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:samba-dev");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:samba-dsdb-modules");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:samba-libs");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:samba-testsuite");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:samba-vfs-modules");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:smbclient");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:winbind");
  script_end_attributes();

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

  script_copyright(english:"Ubuntu Security Notice (C) 2021-2023 Canonical, Inc. / NASL script (C) 2021-2023 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)) audit(AUDIT_OS_NOT, 'Ubuntu 18.04', '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': 'ctdb', 'pkgver': '2:4.7.6+dfsg~ubuntu-0ubuntu2.26'},
    {'osver': '18.04', 'pkgname': 'libnss-winbind', 'pkgver': '2:4.7.6+dfsg~ubuntu-0ubuntu2.26'},
    {'osver': '18.04', 'pkgname': 'libpam-winbind', 'pkgver': '2:4.7.6+dfsg~ubuntu-0ubuntu2.26'},
    {'osver': '18.04', 'pkgname': 'libparse-pidl-perl', 'pkgver': '2:4.7.6+dfsg~ubuntu-0ubuntu2.26'},
    {'osver': '18.04', 'pkgname': 'libsmbclient', 'pkgver': '2:4.7.6+dfsg~ubuntu-0ubuntu2.26'},
    {'osver': '18.04', 'pkgname': 'libsmbclient-dev', 'pkgver': '2:4.7.6+dfsg~ubuntu-0ubuntu2.26'},
    {'osver': '18.04', 'pkgname': 'libwbclient-dev', 'pkgver': '2:4.7.6+dfsg~ubuntu-0ubuntu2.26'},
    {'osver': '18.04', 'pkgname': 'libwbclient0', 'pkgver': '2:4.7.6+dfsg~ubuntu-0ubuntu2.26'},
    {'osver': '18.04', 'pkgname': 'python-samba', 'pkgver': '2:4.7.6+dfsg~ubuntu-0ubuntu2.26'},
    {'osver': '18.04', 'pkgname': 'registry-tools', 'pkgver': '2:4.7.6+dfsg~ubuntu-0ubuntu2.26'},
    {'osver': '18.04', 'pkgname': 'samba', 'pkgver': '2:4.7.6+dfsg~ubuntu-0ubuntu2.26'},
    {'osver': '18.04', 'pkgname': 'samba-common', 'pkgver': '2:4.7.6+dfsg~ubuntu-0ubuntu2.26'},
    {'osver': '18.04', 'pkgname': 'samba-common-bin', 'pkgver': '2:4.7.6+dfsg~ubuntu-0ubuntu2.26'},
    {'osver': '18.04', 'pkgname': 'samba-dev', 'pkgver': '2:4.7.6+dfsg~ubuntu-0ubuntu2.26'},
    {'osver': '18.04', 'pkgname': 'samba-dsdb-modules', 'pkgver': '2:4.7.6+dfsg~ubuntu-0ubuntu2.26'},
    {'osver': '18.04', 'pkgname': 'samba-libs', 'pkgver': '2:4.7.6+dfsg~ubuntu-0ubuntu2.26'},
    {'osver': '18.04', 'pkgname': 'samba-testsuite', 'pkgver': '2:4.7.6+dfsg~ubuntu-0ubuntu2.26'},
    {'osver': '18.04', 'pkgname': 'samba-vfs-modules', 'pkgver': '2:4.7.6+dfsg~ubuntu-0ubuntu2.26'},
    {'osver': '18.04', 'pkgname': 'smbclient', 'pkgver': '2:4.7.6+dfsg~ubuntu-0ubuntu2.26'},
    {'osver': '18.04', 'pkgname': 'winbind', 'pkgver': '2:4.7.6+dfsg~ubuntu-0ubuntu2.26'}
];

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_HOLE,
    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, 'ctdb / libnss-winbind / libpam-winbind / libparse-pidl-perl / etc');
}