NewStart CGSL CORE 5.04 / MAIN 5.04 : nettle Vulnerability (NS-SA-2021-0109)

#%NASL_MIN_LEVEL 70300
##
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from ZTE advisory NS-SA-2021-0109. The text
# itself is copyright (C) ZTE, Inc.
##

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

if (description)
{
  script_id(154530);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2021/10/27");

  script_cve_id("CVE-2021-20305");

  script_name(english:"NewStart CGSL CORE 5.04 / MAIN 5.04 : nettle Vulnerability (NS-SA-2021-0109)");

  script_set_attribute(attribute:"synopsis", value:
"The remote NewStart CGSL host is affected by a vulnerability.");
  script_set_attribute(attribute:"description", value:
"The remote NewStart CGSL host, running version CORE 5.04 / MAIN 5.04, has nettle packages installed that are affected by
a vulnerability:

  - A flaw was found in Nettle in versions before 3.7.2, where several Nettle signature verification functions
    (GOST DSA, EDDSA & ECDSA) result in the Elliptic Curve Cryptography point (ECC) multiply function being
    called with out-of-range scalers, possibly resulting in incorrect results. This flaw allows an attacker to
    force an invalid signature, causing an assertion failure or possible validation. The highest threat to
    this vulnerability is to confidentiality, integrity, as well as system availability. (CVE-2021-20305)

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:"http://security.gd-linux.com/notice/NS-SA-2021-0109");
  script_set_attribute(attribute:"see_also", value:"http://security.gd-linux.com/info/CVE-2021-20305");
  script_set_attribute(attribute:"solution", value:
"Upgrade the vulnerable CGSL nettle packages. Note that updated packages may not be available yet. Please contact ZTE for
more information.");
  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-2021-20305");

  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:"2021/04/05");
  script_set_attribute(attribute:"patch_publication_date", value:"2021/09/24");
  script_set_attribute(attribute:"plugin_publication_date", value:"2021/10/27");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:zte:cgsl_core:nettle");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:zte:cgsl_core:nettle-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:zte:cgsl_core:nettle-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:zte:cgsl_main:nettle");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:zte:cgsl_main:nettle-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:zte:cgsl_main:nettle-devel");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:zte:cgsl_core:5");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:zte:cgsl_main:5");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2021 and is owned by Tenable, Inc. or an Affiliate thereof.");

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

  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);

var release = get_kb_item('Host/ZTE-CGSL/release');
if (isnull(release) || release !~ "^CGSL (MAIN|CORE)") audit(AUDIT_OS_NOT, 'NewStart Carrier Grade Server Linux');

if (release !~ "CGSL CORE 5.04" &&
    release !~ "CGSL MAIN 5.04")
  audit(AUDIT_OS_NOT, 'NewStart CGSL CORE 5.04 / NewStart CGSL MAIN 5.04');

if (!get_kb_item('Host/ZTE-CGSL/rpm-list')) 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$") audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'NewStart Carrier Grade Server Linux', cpu);

var flag = 0;

var pkgs = {
  'CGSL CORE 5.04': [
    'nettle-2.7.1-9.el7_9',
    'nettle-debuginfo-2.7.1-9.el7_9',
    'nettle-devel-2.7.1-9.el7_9'
  ],
  'CGSL MAIN 5.04': [
    'nettle-2.7.1-9.el7_9',
    'nettle-debuginfo-2.7.1-9.el7_9',
    'nettle-devel-2.7.1-9.el7_9'
  ]
};
var pkg_list = pkgs[release];

foreach (pkg in pkg_list)
  if (rpm_check(release:'ZTE ' + release, reference:pkg)) flag++;

if (flag)
{
  security_report_v4(
    port       : 0,
    severity   : SECURITY_WARNING,
    extra      : rpm_report_get()
  );
  exit(0);
}
else
{
  var tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, 'nettle');
}