AlmaLinux 8 : grub2 (ALSA-2022:2110)

##
# (C) Tenable, Inc.
#
# The package checks in this plugin were extracted from
# AlmaLinux Security Advisory ALSA-2022:2110.
##

include('compat.inc');

if (description)
{
  script_id(161091);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2022/05/12");

  script_cve_id("CVE-2021-3981");
  script_xref(name:"ALSA", value:"2022:2110");

  script_name(english:"AlmaLinux 8 : grub2 (ALSA-2022:2110)");

  script_set_attribute(attribute:"synopsis", value:
"The remote AlmaLinux host is missing a security update.");
  script_set_attribute(attribute:"description", value:
"The remote AlmaLinux 8 host has packages installed that are affected by a vulnerability as referenced in the
ALSA-2022:2110 advisory.

  - A flaw in grub2 was found where its configuration file, known as grub.cfg, is being created with the wrong
    permission set allowing non privileged users to read its content. This represents a low severity
    confidentiality issue, as those users can eventually read any encrypted passwords present in grub.cfg.
    This flaw affects grub2 2.06 and previous versions. This issue has been fixed in grub upstream but no
    version with the fix is currently released. (CVE-2021-3981)

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:"https://errata.almalinux.org/8/ALSA-2022-2110.html");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:N/C:P/I:N/A:N");
  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:L/I:N/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-2021-3981");

  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:"2022/03/10");
  script_set_attribute(attribute:"patch_publication_date", value:"2022/05/10");
  script_set_attribute(attribute:"plugin_publication_date", value:"2022/05/12");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alma:linux:grub2-common");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alma:linux:grub2-efi-aa64");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alma:linux:grub2-efi-aa64-cdboot");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alma:linux:grub2-efi-aa64-modules");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alma:linux:grub2-efi-ia32");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alma:linux:grub2-efi-ia32-cdboot");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alma:linux:grub2-efi-ia32-modules");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alma:linux:grub2-efi-x64");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alma:linux:grub2-efi-x64-cdboot");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alma:linux:grub2-efi-x64-modules");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alma:linux:grub2-pc");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alma:linux:grub2-pc-modules");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alma:linux:grub2-ppc64le-modules");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alma:linux:grub2-tools");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alma:linux:grub2-tools-efi");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alma:linux:grub2-tools-extra");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:alma:linux:grub2-tools-minimal");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:alma:linux:8");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Alma Linux Local Security Checks");

  script_copyright(english:"This script is Copyright (C) 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/AlmaLinux/release", "Host/AlmaLinux/rpm-list", "Host/cpu");

  exit(0);
}


include('rpm.inc');

if (!get_kb_item('Host/local_checks_enabled')) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
var release = get_kb_item('Host/AlmaLinux/release');
if (isnull(release) || 'AlmaLinux' >!< release) audit(AUDIT_OS_NOT, 'AlmaLinux');
var os_ver = pregmatch(pattern: "AlmaLinux release ([0-9]+(\.[0-9]+)?)", string:release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, 'AlmaLinux');
var os_ver = os_ver[1];
if (! preg(pattern:"^8([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, 'AlmaLinux 8.x', 'AlmaLinux ' + os_ver);

if (!get_kb_item('Host/AlmaLinux/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) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'AlmaLinux', cpu);

var pkgs = [
    {'reference':'grub2-common-2.02-123.el8.alma', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
    {'reference':'grub2-efi-aa64-2.02-123.el8.alma', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
    {'reference':'grub2-efi-aa64-cdboot-2.02-123.el8.alma', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
    {'reference':'grub2-efi-aa64-modules-2.02-123.el8.alma', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
    {'reference':'grub2-efi-ia32-2.02-123.el8.alma', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
    {'reference':'grub2-efi-ia32-cdboot-2.02-123.el8.alma', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
    {'reference':'grub2-efi-ia32-modules-2.02-123.el8.alma', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
    {'reference':'grub2-efi-x64-2.02-123.el8.alma', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
    {'reference':'grub2-efi-x64-cdboot-2.02-123.el8.alma', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
    {'reference':'grub2-efi-x64-modules-2.02-123.el8.alma', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
    {'reference':'grub2-pc-2.02-123.el8.alma', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
    {'reference':'grub2-pc-modules-2.02-123.el8.alma', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
    {'reference':'grub2-ppc64le-modules-2.02-123.el8.alma', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
    {'reference':'grub2-tools-2.02-123.el8.alma', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
    {'reference':'grub2-tools-2.02-123.el8.alma', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
    {'reference':'grub2-tools-efi-2.02-123.el8.alma', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
    {'reference':'grub2-tools-extra-2.02-123.el8.alma', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
    {'reference':'grub2-tools-extra-2.02-123.el8.alma', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
    {'reference':'grub2-tools-minimal-2.02-123.el8.alma', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
    {'reference':'grub2-tools-minimal-2.02-123.el8.alma', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'}
];

var flag = 0;
foreach var package_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;
  if (!empty_or_null(package_array['reference'])) reference = package_array['reference'];
  if (!empty_or_null(package_array['release'])) release = 'Alma-' + package_array['release'];
  if (!empty_or_null(package_array['sp'])) sp = package_array['sp'];
  if (!empty_or_null(package_array['cpu'])) cpu = package_array['cpu'];
  if (!empty_or_null(package_array['el_string'])) el_string = package_array['el_string'];
  if (!empty_or_null(package_array['rpm_spec_vers_cmp'])) rpm_spec_vers_cmp = package_array['rpm_spec_vers_cmp'];
  if (!empty_or_null(package_array['epoch'])) epoch = package_array['epoch'];
  if (!empty_or_null(package_array['allowmaj'])) allowmaj = package_array['allowmaj'];
  if (!empty_or_null(package_array['exists_check'])) exists_check = package_array['exists_check'];
  if (reference && release && (!exists_check || rpm_exists(release:release, rpm:exists_check))) {
    if (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)) flag++;
  }
}

if (flag)
{
  security_report_v4(
      port       : 0,
      severity   : SECURITY_NOTE,
      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, 'grub2-common / grub2-efi-aa64 / grub2-efi-aa64-cdboot / etc');
}