Oracle Linux 8 : grub2, / mokutil, / shim, / and / shim-unsigned-x64 (ELSA-2022-5095)

##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Oracle Linux Security Advisory ELSA-2022-5095.
##

include('compat.inc');

if (description)
{
  script_id(162717);
  script_version("1.6");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/01/18");

  script_cve_id(
    "CVE-2021-3695",
    "CVE-2021-3696",
    "CVE-2021-3697",
    "CVE-2022-28733",
    "CVE-2022-28734",
    "CVE-2022-28735",
    "CVE-2022-28736",
    "CVE-2022-28737"
  );

  script_name(english:"Oracle Linux 8 : grub2, / mokutil, / shim, / and / shim-unsigned-x64 (ELSA-2022-5095)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Oracle Linux host is missing one or more security updates.");
  script_set_attribute(attribute:"description", value:
"The remote Oracle Linux 8 host has packages installed that are affected by multiple vulnerabilities as referenced in the
ELSA-2022-5095 advisory.

  - shim: Buffer overflow when loading crafted EFI images (CVE-2022-28737)

  - grub2: Crafted PNG image may lead to out-of-bound write during huffman table handling (CVE-2021-3696)

  - grub2: Out-of-bound write when handling split HTTP headers (CVE-2022-28734)

  - grub2: Crafted PNG grayscale images may lead to out-of-bounds write in heap (CVE-2021-3695)

  - grub2: Crafted JPEG image can lead to buffer underflow write in the heap (CVE-2021-3697)

  - grub2: Integer underflow in grub_net_recv_ip4_packets (CVE-2022-28733)

  - grub2: shim_lock verifier allows non-kernel files to be loaded (CVE-2022-28735)

  - grub2: use-after-free in grub_cmd_chainloader() (CVE-2022-28736)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version
number.");
  script_set_attribute(attribute:"see_also", value:"https://linux.oracle.com/errata/ELSA-2022-5095.html");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:M/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: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-2021-3696");
  script_set_attribute(attribute:"cvss3_score_source", value:"CVE-2022-28733");

  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:"2022/06/16");
  script_set_attribute(attribute:"patch_publication_date", value:"2022/07/04");
  script_set_attribute(attribute:"plugin_publication_date", value:"2022/07/05");

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

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

  script_copyright(english:"This script is Copyright (C) 2022-2024 and is owned by Tenable, Inc. or an Affiliate thereof.");

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

  exit(0);
}


include('rpm.inc');

if (!get_kb_item('Host/local_checks_enabled')) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
if (!get_kb_item('Host/OracleLinux')) audit(AUDIT_OS_NOT, 'Oracle Linux');
var release = get_kb_item("Host/RedHat/release");
if (isnull(release) || !pregmatch(pattern: "Oracle (?:Linux Server|Enterprise Linux)", string:release)) audit(AUDIT_OS_NOT, 'Oracle Linux');
var os_ver = pregmatch(pattern: "Oracle (?:Linux Server|Enterprise Linux) .*release ([0-9]+(\.[0-9]+)?)", string:release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, 'Oracle Linux');
var os_ver = os_ver[1];
if (! preg(pattern:"^8([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, 'Oracle Linux 8', 'Oracle Linux ' + 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$" && 'aarch64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'Oracle Linux', cpu);

var pkgs = [
    {'reference':'grub2-common-2.02-123.0.4.el8_6.8', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
    {'reference':'grub2-efi-aa64-2.02-123.0.4.el8_6.8', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
    {'reference':'grub2-efi-aa64-cdboot-2.02-123.0.4.el8_6.8', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
    {'reference':'grub2-efi-aa64-modules-2.02-123.0.4.el8_6.8', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
    {'reference':'grub2-efi-ia32-2.02-123.0.4.el8_6.8', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
    {'reference':'grub2-efi-ia32-cdboot-2.02-123.0.4.el8_6.8', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
    {'reference':'grub2-efi-ia32-modules-2.02-123.0.4.el8_6.8', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
    {'reference':'grub2-efi-x64-2.02-123.0.4.el8_6.8', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
    {'reference':'grub2-efi-x64-cdboot-2.02-123.0.4.el8_6.8', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
    {'reference':'grub2-efi-x64-modules-2.02-123.0.4.el8_6.8', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
    {'reference':'grub2-pc-2.02-123.0.4.el8_6.8', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
    {'reference':'grub2-pc-modules-2.02-123.0.4.el8_6.8', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
    {'reference':'grub2-tools-2.02-123.0.4.el8_6.8', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
    {'reference':'grub2-tools-2.02-123.0.4.el8_6.8', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
    {'reference':'grub2-tools-efi-2.02-123.0.4.el8_6.8', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
    {'reference':'grub2-tools-extra-2.02-123.0.4.el8_6.8', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
    {'reference':'grub2-tools-extra-2.02-123.0.4.el8_6.8', 'cpu':'x86_64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
    {'reference':'grub2-tools-minimal-2.02-123.0.4.el8_6.8', 'cpu':'aarch64', 'release':'8', 'rpm_spec_vers_cmp':TRUE, 'epoch':'1'},
    {'reference':'grub2-tools-minimal-2.02-123.0.4.el8_6.8', '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 = 'EL' + 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) {
    if (exists_check) {
        if (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)) flag++;
    } else {
        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_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, 'grub2-common / grub2-efi-aa64 / grub2-efi-aa64-cdboot / etc');
}