CBL Mariner 2.0 Security Update: kernel (CVE-2025-21731)

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

include('compat.inc');

if (description)
{
  script_id(235326);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2025/05/06");

  script_cve_id("CVE-2025-21731");

  script_name(english:"CBL Mariner 2.0 Security Update: kernel (CVE-2025-21731)");

  script_set_attribute(attribute:"synopsis", value:
"The remote CBL Mariner host is missing one or more security updates.");
  script_set_attribute(attribute:"description", value:
"The version of kernel installed on the remote CBL Mariner 2.0 host is prior to tested version. It is, therefore,
affected by a vulnerability as referenced in the CVE-2025-21731 advisory.

  - In the Linux kernel, the following vulnerability has been resolved: nbd: don't allow reconnect after
    disconnect Following process can cause nbd_config UAF: 1) grab nbd_config temporarily; 2)
    nbd_genl_disconnect() flush all recv_work() and release the initial reference: nbd_genl_disconnect
    nbd_disconnect_and_put nbd_disconnect flush_workqueue(nbd->recv_workq) if
    (test_and_clear_bit(NBD_RT_HAS_CONFIG_REF, ...)) nbd_config_put -> due to step 1), reference is still not
    zero 3) nbd_genl_reconfigure() queue recv_work() again; nbd_genl_reconfigure config =
    nbd_get_config_unlocked(nbd) if (!config) -> succeed if (!test_bit(NBD_RT_BOUND, ...)) -> succeed
    nbd_reconnect_socket queue_work(nbd->recv_workq, &args->work) 4) step 1) release the reference; 5)
    Finially, recv_work() will trigger UAF: recv_work nbd_config_put(nbd) -> nbd_config is freed
    atomic_dec(&config->recv_threads) -> UAF Fix the problem by clearing NBD_RT_BOUND in
    nbd_genl_disconnect(), so that nbd_genl_reconfigure() will fail. (CVE-2025-21731)

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://nvd.nist.gov/vuln/detail/CVE-2025-21731");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages.");
  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: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-2025-21731");

  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:"2025/02/27");
  script_set_attribute(attribute:"patch_publication_date", value:"2025/05/01");
  script_set_attribute(attribute:"plugin_publication_date", value:"2025/05/06");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:microsoft:cbl-mariner:bpftool");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:microsoft:cbl-mariner:kernel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:microsoft:cbl-mariner:kernel-devel");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:microsoft:cbl-mariner:kernel-docs");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:microsoft:cbl-mariner:kernel-drivers-accessibility");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:microsoft:cbl-mariner:kernel-drivers-gpu");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:microsoft:cbl-mariner:kernel-drivers-sound");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:microsoft:cbl-mariner:kernel-dtb");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:microsoft:cbl-mariner:kernel-tools");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:microsoft:cbl-mariner:python3-perf");
  script_set_attribute(attribute:"cpe", value:"x-cpe:/o:microsoft:cbl-mariner");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2025 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("ssh_get_info2.nasl");
  script_require_keys("Host/local_checks_enabled", "Host/CBLMariner/release", "Host/CBLMariner/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/CBLMariner/release');
if (isnull(release) || 'CBL-Mariner' >!< release) audit(AUDIT_OS_NOT, 'CBL-Mariner');
var os_ver = pregmatch(pattern: "CBL-Mariner ([0-9]+(\.[0-9]+)?)", string:release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, 'CBL-Mariner');
os_ver = os_ver[1];
if (! preg(pattern:"^2([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, 'CBL-Mariner 2.0', 'CBL-Mariner ' + os_ver);

if (!get_kb_item('Host/CBLMariner/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, 'CBL-Mariner', cpu);

var pkgs = [
    {'reference':'bpftool-5.15.180.1-1.cm2', 'cpu':'aarch64', 'release':'2.0', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'bpftool-5.15.180.1-1.cm2', 'cpu':'x86_64', 'release':'2.0', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-5.15.180.1-1.cm2', 'cpu':'aarch64', 'release':'2.0', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-5.15.180.1-1.cm2', 'cpu':'x86_64', 'release':'2.0', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-devel-5.15.180.1-1.cm2', 'cpu':'aarch64', 'release':'2.0', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-devel-5.15.180.1-1.cm2', 'cpu':'x86_64', 'release':'2.0', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-docs-5.15.180.1-1.cm2', 'cpu':'aarch64', 'release':'2.0', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-docs-5.15.180.1-1.cm2', 'cpu':'x86_64', 'release':'2.0', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-drivers-accessibility-5.15.180.1-1.cm2', 'cpu':'aarch64', 'release':'2.0', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-drivers-accessibility-5.15.180.1-1.cm2', 'cpu':'x86_64', 'release':'2.0', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-drivers-gpu-5.15.180.1-1.cm2', 'cpu':'aarch64', 'release':'2.0', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-drivers-gpu-5.15.180.1-1.cm2', 'cpu':'x86_64', 'release':'2.0', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-drivers-sound-5.15.180.1-1.cm2', 'cpu':'aarch64', 'release':'2.0', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-drivers-sound-5.15.180.1-1.cm2', 'cpu':'x86_64', 'release':'2.0', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-dtb-5.15.180.1-1.cm2', 'cpu':'aarch64', 'release':'2.0', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-tools-5.15.180.1-1.cm2', 'cpu':'aarch64', 'release':'2.0', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'kernel-tools-5.15.180.1-1.cm2', 'cpu':'x86_64', 'release':'2.0', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'python3-perf-5.15.180.1-1.cm2', 'cpu':'aarch64', 'release':'2.0', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'python3-perf-5.15.180.1-1.cm2', 'cpu':'x86_64', 'release':'2.0', '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 = 'CBLMariner-' + 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, 'bpftool / kernel / kernel-devel / kernel-docs / etc');
}