CBL Mariner 2.0 Security Update: kernel (CVE-2025-21700)

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

include('compat.inc');

if (description)
{
  script_id(235185);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2025/05/06");

  script_cve_id("CVE-2025-21700");

  script_name(english:"CBL Mariner 2.0 Security Update: kernel (CVE-2025-21700)");

  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-2025-21700 advisory.

  - In the Linux kernel, the following vulnerability has been resolved: net: sched: Disallow replacing of
    child qdisc from one parent to another Lion Ackermann was able to create a UAF which can be abused for
    privilege escalation with the following script Step 1. create root qdisc tc qdisc add dev lo root handle
    1:0 drr step2. a class for packet aggregation do demonstrate uaf tc class add dev lo classid 1:1 drr
    step3. a class for nesting tc class add dev lo classid 1:2 drr step4. a class to graft qdisc to tc class
    add dev lo classid 1:3 drr step5. tc qdisc add dev lo parent 1:1 handle 2:0 plug limit 1024 step6. tc
    qdisc add dev lo parent 1:2 handle 3:0 drr step7. tc class add dev lo classid 3:1 drr step 8. tc qdisc add
    dev lo parent 3:1 handle 4:0 pfifo step 9. Display the class/qdisc layout tc class ls dev lo class drr 1:1
    root leaf 2: quantum 64Kb class drr 1:2 root leaf 3: quantum 64Kb class drr 3:1 root leaf 4: quantum 64Kb
    tc qdisc ls qdisc drr 1: dev lo root refcnt 2 qdisc plug 2: dev lo parent 1:1 qdisc pfifo 4: dev lo parent
    3:1 limit 1000p qdisc drr 3: dev lo parent 1:2 step10. trigger the bug <=== prevented by this patch tc
    qdisc replace dev lo parent 1:3 handle 4:0 step 11. Redisplay again the qdiscs/classes tc class ls dev lo
    class drr 1:1 root leaf 2: quantum 64Kb class drr 1:2 root leaf 3: quantum 64Kb class drr 1:3 root leaf 4:
    quantum 64Kb class drr 3:1 root leaf 4: quantum 64Kb tc qdisc ls qdisc drr 1: dev lo root refcnt 2 qdisc
    plug 2: dev lo parent 1:1 qdisc pfifo 4: dev lo parent 3:1 refcnt 2 limit 1000p qdisc drr 3: dev lo parent
    1:2 Observe that a) parent for 4:0 does not change despite the replace request. There can only be one
    parent. b) refcount has gone up by two for 4:0 and c) both class 1:3 and 3:1 are pointing to it. Step 12.
    send one packet to plug echo  | socat -u STDIN UDP4-DATAGRAM:127.0.0.1:8888,priority=$((0x10001))
    step13. send one packet to the grafted fifo echo  | socat -u STDIN
    UDP4-DATAGRAM:127.0.0.1:8888,priority=$((0x10003)) step14. lets trigger the uaf tc class delete dev lo
    classid 1:3 tc class delete dev lo classid 1:1 The semantics of replace is for a del/add _on the same
    node_ and not a delete from one node(3:1) and add to another node (1:3) as in step10. While we could fix
    with a more complex approach there could be consequences to expectations so the patch takes the preventive
    approach of disallow such config. Joint work with Lion Ackermann <[email protected]> (CVE-2025-21700)

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-2025-21700");
  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-2025-21700");

  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:"2025/02/13");
  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');
}