Ubuntu 16.04 LTS / 18.04 LTS / 20.04 LTS : NSS vulnerabilities (USN-4397-1)

#
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Ubuntu Security Notice USN-4397-1. 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(137555);
  script_version("1.8");
  script_set_attribute(attribute:"plugin_modification_date", value:"2023/10/21");

  script_cve_id("CVE-2019-17023", "CVE-2020-12399");
  script_xref(name:"USN", value:"4397-1");

  script_name(english:"Ubuntu 16.04 LTS / 18.04 LTS / 20.04 LTS : NSS vulnerabilities (USN-4397-1)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Ubuntu host is missing one or more security updates.");
  script_set_attribute(attribute:"description", value:
"It was discovered that NSS incorrectly handled the TLS State Machine.
A remote attacker could possibly use this issue to cause NSS to hang,
resulting in a denial of service. This issue only affected Ubuntu
18.04 LTS and Ubuntu 19.10. (CVE-2019-17023)

Cesar Pereida Garcia discovered that NSS incorrectly handled DSA key
generation. A local attacker could possibly use this issue to perform
a timing attack and recover DSA keys. (CVE-2020-12399).

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://ubuntu.com/security/notices/USN-4397-1");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:N/I:P/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:N/UI:R/S:U/C:N/I:H/A:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2019-17023");

  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:"2020/01/08");
  script_set_attribute(attribute:"patch_publication_date", value:"2020/06/16");
  script_set_attribute(attribute:"plugin_publication_date", value:"2020/06/17");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libnss3");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libnss3-1d");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libnss3-dev");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libnss3-nssdb");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:canonical:ubuntu_linux:libnss3-tools");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:canonical:ubuntu_linux:16.04:-:lts");
  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:"generated_plugin", value:"current");
  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 (! ('16.04' >< os_release || '18.04' >< os_release || '20.04' >< os_release)) audit(AUDIT_OS_NOT, 'Ubuntu 16.04 / 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': '16.04', 'pkgname': 'libnss3', 'pkgver': '2:3.28.4-0ubuntu0.16.04.11'},
    {'osver': '16.04', 'pkgname': 'libnss3-1d', 'pkgver': '2:3.28.4-0ubuntu0.16.04.11'},
    {'osver': '16.04', 'pkgname': 'libnss3-dev', 'pkgver': '2:3.28.4-0ubuntu0.16.04.11'},
    {'osver': '16.04', 'pkgname': 'libnss3-nssdb', 'pkgver': '2:3.28.4-0ubuntu0.16.04.11'},
    {'osver': '16.04', 'pkgname': 'libnss3-tools', 'pkgver': '2:3.28.4-0ubuntu0.16.04.11'},
    {'osver': '18.04', 'pkgname': 'libnss3', 'pkgver': '2:3.35-2ubuntu2.8'},
    {'osver': '18.04', 'pkgname': 'libnss3-dev', 'pkgver': '2:3.35-2ubuntu2.8'},
    {'osver': '18.04', 'pkgname': 'libnss3-tools', 'pkgver': '2:3.35-2ubuntu2.8'},
    {'osver': '20.04', 'pkgname': 'libnss3', 'pkgver': '2:3.49.1-1ubuntu1.1'},
    {'osver': '20.04', 'pkgname': 'libnss3-dev', 'pkgver': '2:3.49.1-1ubuntu1.1'},
    {'osver': '20.04', 'pkgname': 'libnss3-tools', 'pkgver': '2:3.49.1-1ubuntu1.1'}
];

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, 'libnss3 / libnss3-1d / libnss3-dev / libnss3-nssdb / libnss3-tools');
}