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nessusThis script is Copyright (C) 2020-2024 and is owned by Tenable, Inc. or an Affiliate thereof.REDHAT-RHSA-2020-2210.NASL
HistoryMay 20, 2020 - 12:00 a.m.

RHEL 7 : ksh (RHSA-2020:2210)

2020-05-2000:00:00
This script is Copyright (C) 2020-2024 and is owned by Tenable, Inc. or an Affiliate thereof.
www.tenable.com
10

7.2 High

CVSS2

Attack Vector

LOCAL

Attack Complexity

LOW

Authentication

NONE

Confidentiality Impact

COMPLETE

Integrity Impact

COMPLETE

Availability Impact

COMPLETE

AV:L/AC:L/Au:N/C:C/I:C/A:C

7.8 High

CVSS3

Attack Vector

LOCAL

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

8.1 High

AI Score

Confidence

High

0.002 Low

EPSS

Percentile

57.2%

The remote Redhat Enterprise Linux 7 host has a package installed that is affected by a vulnerability as referenced in the RHSA-2020:2210 advisory.

KornShell (ksh) is a Unix shell developed by AT&T Bell Laboratories, which is backward-compatible with the     Bourne shell (sh) and includes many features of the C shell. The most recent version is KSH-93. KornShell     complies with the POSIX.2 standard (IEEE Std 1003.2-1992).

Security Fix(es):

* ksh: certain environment variables interpreted as arithmetic expressions on startup, leading to code     injection (CVE-2019-14868)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and     other related information, refer to the CVE page(s) listed in the References section.

Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application’s self-reported version number.

##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Red Hat Security Advisory RHSA-2020:2210. The text
# itself is copyright (C) Red Hat, Inc.
##

include('compat.inc');

if (description)
{
  script_id(136713);
  script_version("1.8");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/06/04");

  script_cve_id("CVE-2019-14868");
  script_xref(name:"RHSA", value:"2020:2210");

  script_name(english:"RHEL 7 : ksh (RHSA-2020:2210)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Red Hat host is missing a security update for ksh.");
  script_set_attribute(attribute:"description", value:
"The remote Redhat Enterprise Linux 7 host has a package installed that is affected by a vulnerability as referenced in
the RHSA-2020:2210 advisory.

    KornShell (ksh) is a Unix shell developed by AT&T Bell Laboratories, which is backward-compatible with the
    Bourne shell (sh) and includes many features of the C shell. The most recent version is KSH-93. KornShell
    complies with the POSIX.2 standard (IEEE Std 1003.2-1992).

    Security Fix(es):

    * ksh: certain environment variables interpreted as arithmetic expressions on startup, leading to code
    injection (CVE-2019-14868)

    For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and
    other related information, refer to the CVE page(s) listed in the References section.

Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version
number.");
  # https://access.redhat.com/security/data/csaf/v2/advisories/2020/rhsa-2020_2210.json
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?1134577a");
  script_set_attribute(attribute:"see_also", value:"https://access.redhat.com/security/updates/classification/#important");
  script_set_attribute(attribute:"see_also", value:"https://access.redhat.com/errata/RHSA-2020:2210");
  script_set_attribute(attribute:"see_also", value:"https://bugzilla.redhat.com/show_bug.cgi?id=1757324");
  script_set_attribute(attribute:"solution", value:
"Update the RHEL ksh package based on the guidance in RHSA-2020:2210.");
  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:"exploit_available", value:"false");
  script_cwe_id(77);
  script_set_attribute(attribute:"vendor_severity", value:"Important");

  script_set_attribute(attribute:"vuln_publication_date", value:"2020/02/07");
  script_set_attribute(attribute:"patch_publication_date", value:"2020/05/19");
  script_set_attribute(attribute:"plugin_publication_date", value:"2020/05/20");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:rhel_aus:7.4");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:rhel_e4s:7.4");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:redhat:rhel_tus:7.4");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:redhat:enterprise_linux:ksh");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2020-2024 and is owned by Tenable, Inc. or an Affiliate thereof.");

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

  exit(0);
}


include('rpm.inc');
include('rhel.inc');

if (!get_kb_item('Host/local_checks_enabled')) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
var os_release = get_kb_item('Host/RedHat/release');
if (isnull(os_release) || 'Red Hat' >!< os_release) audit(AUDIT_OS_NOT, 'Red Hat');
var os_ver = pregmatch(pattern: "Red Hat Enterprise Linux.*release ([0-9]+(\.[0-9]+)?)", string:os_release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, 'Red Hat');
os_ver = os_ver[1];
if (!rhel_check_release(operator: 'eq', os_version: os_ver, rhel_version: '7.4')) audit(AUDIT_OS_NOT, 'Red Hat 7.4', 'Red Hat ' + os_ver);

if (!get_kb_item('Host/RedHat/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$" && 's390' >!< cpu && 'aarch64' >!< cpu && 'ppc' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'Red Hat', cpu);

var constraints = [
  {
    'repo_relative_urls': [
      'content/aus/rhel/server/7/7.4/x86_64/debug',
      'content/aus/rhel/server/7/7.4/x86_64/optional/debug',
      'content/aus/rhel/server/7/7.4/x86_64/optional/os',
      'content/aus/rhel/server/7/7.4/x86_64/optional/source/SRPMS',
      'content/aus/rhel/server/7/7.4/x86_64/os',
      'content/aus/rhel/server/7/7.4/x86_64/source/SRPMS',
      'content/e4s/rhel/power-le/7/7.4/ppc64le/debug',
      'content/e4s/rhel/power-le/7/7.4/ppc64le/highavailability/debug',
      'content/e4s/rhel/power-le/7/7.4/ppc64le/highavailability/os',
      'content/e4s/rhel/power-le/7/7.4/ppc64le/highavailability/source/SRPMS',
      'content/e4s/rhel/power-le/7/7.4/ppc64le/optional/debug',
      'content/e4s/rhel/power-le/7/7.4/ppc64le/optional/os',
      'content/e4s/rhel/power-le/7/7.4/ppc64le/optional/source/SRPMS',
      'content/e4s/rhel/power-le/7/7.4/ppc64le/os',
      'content/e4s/rhel/power-le/7/7.4/ppc64le/source/SRPMS',
      'content/e4s/rhel/server/7/7.4/x86_64/debug',
      'content/e4s/rhel/server/7/7.4/x86_64/highavailability/debug',
      'content/e4s/rhel/server/7/7.4/x86_64/highavailability/os',
      'content/e4s/rhel/server/7/7.4/x86_64/highavailability/source/SRPMS',
      'content/e4s/rhel/server/7/7.4/x86_64/optional/debug',
      'content/e4s/rhel/server/7/7.4/x86_64/optional/os',
      'content/e4s/rhel/server/7/7.4/x86_64/optional/source/SRPMS',
      'content/e4s/rhel/server/7/7.4/x86_64/os',
      'content/e4s/rhel/server/7/7.4/x86_64/source/SRPMS',
      'content/tus/rhel/server/7/7.4/x86_64/debug',
      'content/tus/rhel/server/7/7.4/x86_64/optional/debug',
      'content/tus/rhel/server/7/7.4/x86_64/optional/os',
      'content/tus/rhel/server/7/7.4/x86_64/optional/source/SRPMS',
      'content/tus/rhel/server/7/7.4/x86_64/os',
      'content/tus/rhel/server/7/7.4/x86_64/source/SRPMS'
    ],
    'pkgs': [
      {'reference':'ksh-20120801-36.el7_4', 'sp':'4', 'cpu':'ppc64le', 'release':'7', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'ksh-20120801-36.el7_4', 'sp':'4', 'cpu':'x86_64', 'release':'7', 'rpm_spec_vers_cmp':TRUE}
    ]
  }
];

var applicable_repo_urls = rhel_determine_applicable_repository_urls(constraints:constraints);
if(applicable_repo_urls == RHEL_REPOS_NO_OVERLAP_MESSAGE) exit(0, RHEL_REPO_NOT_ENABLED);

var flag = 0;
foreach var constraint_array ( constraints ) {
  var repo_relative_urls = NULL;
  if (!empty_or_null(constraint_array['repo_relative_urls'])) repo_relative_urls = constraint_array['repo_relative_urls'];
  foreach var pkg ( constraint_array['pkgs'] ) {
    var reference = NULL;
    var _release = NULL;
    var sp = NULL;
    var _cpu = NULL;
    var el_string = NULL;
    var rpm_spec_vers_cmp = NULL;
    var epoch = NULL;
    var allowmaj = NULL;
    var exists_check = NULL;
    var cves = NULL;
    if (!empty_or_null(pkg['reference'])) reference = pkg['reference'];
    if (!empty_or_null(pkg['release'])) _release = 'RHEL' + pkg['release'];
    if (!empty_or_null(pkg['sp'])) sp = pkg['sp'];
    if (!empty_or_null(pkg['cpu'])) _cpu = pkg['cpu'];
    if (!empty_or_null(pkg['el_string'])) el_string = pkg['el_string'];
    if (!empty_or_null(pkg['rpm_spec_vers_cmp'])) rpm_spec_vers_cmp = pkg['rpm_spec_vers_cmp'];
    if (!empty_or_null(pkg['epoch'])) epoch = pkg['epoch'];
    if (!empty_or_null(pkg['allowmaj'])) allowmaj = pkg['allowmaj'];
    if (!empty_or_null(pkg['exists_check'])) exists_check = pkg['exists_check'];
    if (!empty_or_null(pkg['cves'])) cves = pkg['cves'];
    if (reference &&
        _release &&
        rhel_decide_repo_relative_url_check(required_repo_url_list:repo_relative_urls) &&
        (applicable_repo_urls || (!exists_check || rpm_exists(release:_release, rpm:exists_check))) &&
        rpm_check(release:_release, sp:sp, cpu:_cpu, reference:reference, epoch:epoch, el_string:el_string, rpm_spec_vers_cmp:rpm_spec_vers_cmp, allowmaj:allowmaj, cves:cves)) flag++;
  }
}

if (flag)
{
  var subscription_caveat = '\n' +
    'NOTE: This vulnerability check contains fixes that apply to\n' +
    'packages only available in the Red Hat Enterprise Linux\n' +
    'Advanced Update Support, Telco Extended Update Support or Update Services for SAP Solutions repositories.\n' +
    'Access to these repositories requires a paid RHEL subscription.\n';
  var extra = NULL;
  if (isnull(applicable_repo_urls) || !applicable_repo_urls) extra = subscription_caveat + rpm_report_get() + redhat_report_repo_caveat();
  else extra = subscription_caveat + rpm_report_get();
  security_report_v4(
      port       : 0,
      severity   : SECURITY_HOLE,
      extra      : extra
  );
  exit(0);
}
else
{
  var tested = pkg_tests_get();
  if (tested) audit(AUDIT_PACKAGE_NOT_AFFECTED, tested);
  else audit(AUDIT_PACKAGE_NOT_INSTALLED, 'ksh');
}
VendorProductVersionCPE
redhatrhel_tus7.4cpe:/o:redhat:rhel_tus:7.4
redhatrhel_aus7.4cpe:/o:redhat:rhel_aus:7.4
redhatrhel_e4s7.4cpe:/o:redhat:rhel_e4s:7.4
redhatenterprise_linuxkshp-cpe:/a:redhat:enterprise_linux:ksh

7.2 High

CVSS2

Attack Vector

LOCAL

Attack Complexity

LOW

Authentication

NONE

Confidentiality Impact

COMPLETE

Integrity Impact

COMPLETE

Availability Impact

COMPLETE

AV:L/AC:L/Au:N/C:C/I:C/A:C

7.8 High

CVSS3

Attack Vector

LOCAL

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

8.1 High

AI Score

Confidence

High

0.002 Low

EPSS

Percentile

57.2%