CentOS Linux 7 [TuxCare] Security Update: grub2 / grub2-common / grub2-efi-ia32 / grub2-efi-ia32-cdboot / etc Multiple Vulnerabilities (CENTOS7:CLSA-2026:1771332544)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
##

include('compat.inc');

if (description)
{
  script_id(352919);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/09/30");

  script_cve_id("CVE-2025-0689", "CVE-2025-61662");
  script_xref(name:"CLSA", value:"2026:1771332544");

  script_name(english:"CentOS Linux 7 [TuxCare] Security Update: grub2 / grub2-common / grub2-efi-ia32 / grub2-efi-ia32-cdboot / etc Multiple Vulnerabilities (CENTOS7:CLSA-2026:1771332544)");

  script_set_attribute(attribute:"synopsis", value:
"The CentOS Linux host is missing one or more security updates.");
  script_set_attribute(attribute:"description", value:
"The CentOS Linux 7 host has packages installed that are affected by multiple vulnerabilities as referenced in the
TuxCare CENTOS7:CLSA-2026:1771332544 advisory.

  - When reading data from disk, the grub's UDF filesystem module utilizes the user controlled data length
    metadata to allocate its internal buffers. In certain scenarios, while iterating through disk sectors, it
    assumes the read size from the disk is always smaller than the allocated buffer size which is not
    guaranteed. A crafted filesystem image may lead to a heap-based buffer overflow resulting in critical data
    to be corrupted, resulting in the risk of arbitrary code execution by-passing secure boot protections.
    (CVE-2025-0689)

  - A Use-After-Free vulnerability has been discovered in GRUB's gettext module. This flaw stems from a
    programming error where the gettext command remains registered in memory after its module is unloaded. An
    attacker can exploit this condition by invoking the orphaned command, causing the application to access a
    memory location that is no longer valid. An attacker could exploit this vulnerability to cause grub to
    crash, leading to a Denial of Service. Possible data integrity or confidentiality compromise is not
    discarded. (CVE-2025-61662)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version
number.");
  # https://security.tuxcare.com/csaf/v2/els_os/centos7els/advisories/2026/clsa-2026_1771332544.json
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?a82f9f86");
  script_set_attribute(attribute:"see_also", value:"https://cve.tuxcare.com/els/releases/CLSA-2026:1771332544");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages based on the guidance in TuxCare advisory CENTOS7:CLSA-2026:1771332544.");
  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-2025-0689");
  script_set_attribute(attribute:"cvss3_score_source", value:"CVE-2025-61662");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");
  script_set_attribute(attribute:"vendor_severity", value:"Important");

  script_set_attribute(attribute:"vuln_publication_date", value:"2024/04/11");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/02/17");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/09/30");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2026 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("ssh_get_info2.nasl");
  script_require_keys("Host/OS/extended-third-party", "Host/local_checks_enabled", "Host/CentOS/release", "Host/CentOS/rpm-list");

  exit(0);
}
include('rpm2.inc');

var third_party_support = get_kb_item('Host/OS/extended-third-party');
if (empty_or_null(third_party_support) || third_party_support != 'TuxCare') exit(0, 'TuxCare support not enabled.');

if (!get_kb_item('Host/local_checks_enabled')) audit(AUDIT_LOCAL_CHECKS_NOT_ENABLED);
var os_product = get_kb_item('installed_os/local/SSH/0/product');
if (isnull(os_product) || 'CentOS Linux' >!< os_product) audit(AUDIT_OS_NOT, 'CentOS Linux');
var os_version = get_kb_item('installed_os/local/SSH/0/version');
if (isnull(os_version)) audit(AUDIT_UNKNOWN_APP_VER, 'CentOS Linux');
if (! preg(pattern:"^7([^0-9]|$)", string:os_version)) audit(AUDIT_OS_NOT, 'CentOS Linux 7', 'CentOS Linux ' + os_version);

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


var constraints = [
  {
    'release': '7',
    'pkgs': [
      {'reference':'grub2-2.02-0.87.0.2.el7.centos.14.tuxcare.els9', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE, 'epoch':'3'},
      {'reference':'grub2-common-2.02-0.87.0.2.el7.centos.14.tuxcare.els9', 'rpm_spec_vers_cmp':TRUE, 'epoch':'3'},
      {'reference':'grub2-efi-ia32-2.02-0.87.0.2.el7.centos.14.tuxcare.els9', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE, 'epoch':'3'},
      {'reference':'grub2-efi-ia32-cdboot-2.02-0.87.0.2.el7.centos.14.tuxcare.els9', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE, 'epoch':'3'},
      {'reference':'grub2-efi-ia32-modules-2.02-0.87.0.2.el7.centos.14.tuxcare.els9', 'rpm_spec_vers_cmp':TRUE, 'epoch':'3'},
      {'reference':'grub2-efi-x64-2.02-0.87.0.2.el7.centos.14.tuxcare.els9', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE, 'epoch':'3'},
      {'reference':'grub2-efi-x64-cdboot-2.02-0.87.0.2.el7.centos.14.tuxcare.els9', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE, 'epoch':'3'},
      {'reference':'grub2-efi-x64-modules-2.02-0.87.0.2.el7.centos.14.tuxcare.els9', 'rpm_spec_vers_cmp':TRUE, 'epoch':'3'},
      {'reference':'grub2-i386-modules-2.02-0.87.0.2.el7.centos.14.tuxcare.els9', 'rpm_spec_vers_cmp':TRUE, 'epoch':'3'},
      {'reference':'grub2-pc-2.02-0.87.0.2.el7.centos.14.tuxcare.els9', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE, 'epoch':'3'},
      {'reference':'grub2-pc-modules-2.02-0.87.0.2.el7.centos.14.tuxcare.els9', 'rpm_spec_vers_cmp':TRUE, 'epoch':'3'},
      {'reference':'grub2-tools-2.02-0.87.0.2.el7.centos.14.tuxcare.els9', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE, 'epoch':'3'},
      {'reference':'grub2-tools-extra-2.02-0.87.0.2.el7.centos.14.tuxcare.els9', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE, 'epoch':'3'},
      {'reference':'grub2-tools-minimal-2.02-0.87.0.2.el7.centos.14.tuxcare.els9', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE, 'epoch':'3'}
    ]
  }
];

var os_release = get_one_kb_item('installed_os/local/SSH/0/release');
var os_sp = get_one_kb_item('Host/*/minor_release');

var flag = 0;
var reference;
var sp;
var _cpu;
var el_string;
var rpm_spec_vers_cmp;
var epoch;
var allowmaj;
var exists_check;
var cves;
foreach var constraint ( constraints ) {
  # Check that the target release is equal to the affected release
  if (!empty_or_null(constraint['release'])){
    if (constraint['release'] != os_release) continue;
  }
  if (!empty_or_null(constraint['sp'])){
    if (constraint['sp'] != os_sp) continue;
  }
  foreach var pkg ( constraint['pkgs'] ) {
    reference = NULL;
    sp = NULL;
    _cpu = NULL;
    el_string = NULL;
    rpm_spec_vers_cmp = NULL;
    epoch = NULL;
    allowmaj = NULL;
    exists_check = NULL;
    cves = NULL;
    if (!empty_or_null(pkg['reference'])) reference = pkg['reference'];
    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 &&
        ## (no known rpm to check OR known rpm_exists)
        (!exists_check || rpm_exists(rpm:exists_check)) &&
        rpm_check(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_HOLE,
      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-efi-ia32 / grub2-efi-ia32-cdboot / etc');
}