NewStart CGSL CORE 5.04 / MAIN 5.04 : shim Vulnerability (NS-SA-2021-0009)

##
# (C) Tenable Network Security, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from ZTE advisory NS-SA-2021-0009. The text
# itself is copyright (C) ZTE, Inc.
##

include('compat.inc');

if (description)
{
  script_id(147322);
  script_version("1.4");
  script_set_attribute(attribute:"plugin_modification_date", value:"2022/12/05");

  script_cve_id("CVE-2020-10713");
  script_xref(name:"CEA-ID", value:"CEA-2020-0061");

  script_name(english:"NewStart CGSL CORE 5.04 / MAIN 5.04 : shim Vulnerability (NS-SA-2021-0009)");

  script_set_attribute(attribute:"synopsis", value:
"The remote machine 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 shim packages installed that are affected by a
vulnerability:

  - A flaw was found in grub2, prior to version 2.06. An attacker may use the GRUB 2 flaw to hijack and tamper
    the GRUB verification process. This flaw also allows the bypass of Secure Boot protections. In order to
    load an untrusted or modified kernel, an attacker would first need to establish access to the system such
    as gaining physical access, obtain the ability to alter a pxe-boot network, or have remote access to a
    networked system with root access. With this access, an attacker could then craft a string to cause a
    buffer overflow by injecting a malicious payload that leads to arbitrary code execution within GRUB. The
    highest threat from this vulnerability is to data confidentiality and integrity as well as system
    availability. (CVE-2020-10713)

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-2021-0009");
  script_set_attribute(attribute:"solution", value:
"Upgrade the vulnerable CGSL shim packages. Note that updated packages may not be available yet. Please contact ZTE for
more information.");
  script_set_cvss_base_vector("CVSS2#AV:L/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:L/AC:L/PR:H/UI:N/S:C/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-2020-10713");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");

  script_set_attribute(attribute:"vuln_publication_date", value:"2020/07/29");
  script_set_attribute(attribute:"patch_publication_date", value:"2021/03/09");
  script_set_attribute(attribute:"plugin_publication_date", value:"2021/03/10");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2021-2022 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);

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);

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);

flag = 0;

pkgs = {
  'CGSL CORE 5.04': [
    'shim-unsigned-ia32-15-8.el7',
    'shim-unsigned-ia32-debuginfo-15-8.el7',
    'shim-unsigned-x64-15-8.el7',
    'shim-unsigned-x64-debuginfo-15-8.el7'
  ],
  'CGSL MAIN 5.04': [
    'shim-unsigned-ia32-15-8.el7',
    'shim-unsigned-ia32-debuginfo-15-8.el7',
    'shim-unsigned-x64-15-8.el7',
    'shim-unsigned-x64-debuginfo-15-8.el7'
  ]
};
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
{
  tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, 'shim');
}