Amazon Linux 2 : grub2 (ALAS-2023-2292)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Amazon Linux 2 Security Advisory ALAS-2023-2292.
##

include('compat.inc');

if (description)
{
  script_id(183466);
  script_version("1.3");
  script_set_attribute(attribute:"plugin_modification_date", value:"2024/12/11");

  script_cve_id("CVE-2023-4692", "CVE-2023-4693");

  script_name(english:"Amazon Linux 2 : grub2 (ALAS-2023-2292)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Amazon Linux 2 host is missing a security update.");
  script_set_attribute(attribute:"description", value:
"The version of grub2 installed on the remote host is prior to 2.06-14. It is, therefore, affected by multiple
vulnerabilities as referenced in the ALAS2-2023-2292 advisory.

    An out-of-bounds write flaw was found in grub2's NTFS filesystem driver. This issue may allow an attacker
    to present a specially crafted NTFS filesystem image, leading to grub's heap metadata corruption. In some
    circumstances, the attack may also corrupt the UEFI firmware heap metadata. As a result, arbitrary code
    execution and secure boot protection bypass may be achieved. (CVE-2023-4692)

    An out-of-bounds read flaw was found on grub2's NTFS filesystem driver. This issue may allow a physically
    present attacker to present a specially crafted NTFS file system image to read arbitrary memory locations.
    A successful attack allows sensitive data cached in memory or EFI variable values to be leaked, presenting
    a high Confidentiality risk. (CVE-2023-4693)

Tenable has extracted the preceding description block directly from the tested product security advisory.

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://alas.aws.amazon.com/AL2/ALAS-2023-2292.html");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2023-4692.html");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/cve/html/CVE-2023-4693.html");
  script_set_attribute(attribute:"see_also", value:"https://alas.aws.amazon.com/faqs.html");
  script_set_attribute(attribute:"solution", value:
"Run 'yum update grub2' to update your system.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:S/C:C/I:C/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:POC/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:P/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2023-4692");

  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");

  script_set_attribute(attribute:"vuln_publication_date", value:"2023/10/12");
  script_set_attribute(attribute:"patch_publication_date", value:"2023/10/12");
  script_set_attribute(attribute:"plugin_publication_date", value:"2023/10/20");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:grub2");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:grub2-common");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:grub2-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:grub2-efi-aa64");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:grub2-efi-aa64-cdboot");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:grub2-efi-aa64-ec2");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:grub2-efi-aa64-modules");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:grub2-efi-x64");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:grub2-efi-x64-cdboot");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:grub2-efi-x64-ec2");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:grub2-efi-x64-modules");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:grub2-emu");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:grub2-emu-modules");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:grub2-pc");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:grub2-pc-modules");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:grub2-tools");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:grub2-tools-efi");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:grub2-tools-extra");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:amazon:linux:grub2-tools-minimal");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:amazon:linux:2");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2023-2024 and is owned by Tenable, Inc. or an Affiliate thereof.");

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

  exit(0);
}

include("rpm.inc");

if (!get_kb_item("Host/local_checks_enabled")) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);

var alas_release = get_kb_item("Host/AmazonLinux/release");
if (isnull(alas_release) || !strlen(alas_release)) audit(AUDIT_OS_NOT, "Amazon Linux");
var os_ver = pregmatch(pattern: "^AL(A|\d+|-\d+)", string:alas_release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, "Amazon Linux");
os_ver = os_ver[1];
if (os_ver != "2")
{
  if (os_ver == 'A') os_ver = 'AMI';
  audit(AUDIT_OS_NOT, "Amazon Linux 2", "Amazon Linux " + os_ver);
}

if (!get_kb_item("Host/AmazonLinux/rpm-list")) audit(AUDIT_PACKAGE_LIST_MISSING);

var pkgs = [
    {'reference':'grub2-2.06-14.amzn2.0.2', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'grub2-2.06-14.amzn2.0.2', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'grub2-common-2.06-14.amzn2.0.2', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'grub2-debuginfo-2.06-14.amzn2.0.2', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'grub2-debuginfo-2.06-14.amzn2.0.2', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'grub2-efi-aa64-2.06-14.amzn2.0.2', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'grub2-efi-aa64-cdboot-2.06-14.amzn2.0.2', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'grub2-efi-aa64-ec2-2.06-14.amzn2.0.2', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'grub2-efi-aa64-modules-2.06-14.amzn2.0.2', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'grub2-efi-x64-2.06-14.amzn2.0.2', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'grub2-efi-x64-cdboot-2.06-14.amzn2.0.2', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'grub2-efi-x64-ec2-2.06-14.amzn2.0.2', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'grub2-efi-x64-modules-2.06-14.amzn2.0.2', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'grub2-emu-2.06-14.amzn2.0.2', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'grub2-emu-2.06-14.amzn2.0.2', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'grub2-emu-modules-2.06-14.amzn2.0.2', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'grub2-emu-modules-2.06-14.amzn2.0.2', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'grub2-pc-2.06-14.amzn2.0.2', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'grub2-pc-modules-2.06-14.amzn2.0.2', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'grub2-tools-2.06-14.amzn2.0.2', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'grub2-tools-2.06-14.amzn2.0.2', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'grub2-tools-efi-2.06-14.amzn2.0.2', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'grub2-tools-extra-2.06-14.amzn2.0.2', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'grub2-tools-extra-2.06-14.amzn2.0.2', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'grub2-tools-minimal-2.06-14.amzn2.0.2', 'cpu':'aarch64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'grub2-tools-minimal-2.06-14.amzn2.0.2', 'cpu':'x86_64', 'release':'AL2', 'rpm_spec_vers_cmp':TRUE}
];

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;
  var cves = NULL;
  if (!empty_or_null(package_array['reference'])) reference = package_array['reference'];
  if (!empty_or_null(package_array['release'])) _release = 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 (!empty_or_null(package_array['cves'])) cves = package_array['cves'];
  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, cves:cves)) 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 / grub2-common / grub2-debuginfo / etc");
}