NewStart CGSL MAIN 4.05 : ksh Vulnerability (NS-SA-2020-0046)

#%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-2020-0046. The text
# itself is copyright (C) ZTE, Inc.

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

if (description)
{
  script_id(140290);
  script_version("1.4");
  script_set_attribute(attribute:"plugin_modification_date", value:"2021/01/14");

  script_cve_id("CVE-2019-14868");

  script_name(english:"NewStart CGSL MAIN 4.05 : ksh Vulnerability (NS-SA-2020-0046)");

  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 MAIN 4.05, has ksh packages installed that are affected by a
vulnerability:

  - In ksh version 20120801, a flaw was found in the way it evaluates certain environment variables. An
    attacker could use this flaw to override or bypass environment restrictions to execute shell commands.
    Services and applications that allow remote unauthenticated attackers to provide one of those environment
    variables could allow them to exploit this issue remotely. (CVE-2019-14868)

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-2020-0046");
  script_set_attribute(attribute:"solution", value:
"Upgrade the vulnerable CGSL ksh 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:C/I:C/A:C");
  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: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-2019-14868");

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

  script_set_attribute(attribute:"vuln_publication_date", value:"2020/04/02");
  script_set_attribute(attribute:"patch_publication_date", value:"2020/09/07");
  script_set_attribute(attribute:"plugin_publication_date", value:"2020/09/07");

  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) 2020-2021 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);

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 MAIN 4.05")
  audit(AUDIT_OS_NOT, 'NewStart CGSL MAIN 4.05');

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 MAIN 4.05': [
    'ksh-20120801-38.el6_10',
    'ksh-debuginfo-20120801-38.el6_10'
  ]
};
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_HOLE,
    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, 'ksh');
}