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Azure Linux 3.0 Security Update: hyperv-daemons (CVE-2024-26935)

🗓️ 22 Jan 2026 00:00:00Reported by TenableType 
nessus
 nessus
🔗 www.tenable.com👁 3 Views

Azure Linux 3.0 update fixes CVE 2024 26935 in hyperv-daemons and addresses procfs hostdir regression in the SCSI core.

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

include('compat.inc');

if (description)
{
  script_id(295782);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/01/22");

  script_cve_id("CVE-2024-26935");

  script_name(english:"Azure Linux 3.0 Security Update: hyperv-daemons (CVE-2024-26935)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Azure Linux host is missing one or more security updates.");
  script_set_attribute(attribute:"description", value:
"The version of hyperv-daemons installed on the remote Azure Linux 3.0 host is prior to tested version. It is, therefore,
affected by a vulnerability as referenced in the CVE-2024-26935 advisory.

  - In the Linux kernel, the following vulnerability has been resolved: scsi: core: Fix unremoved procfs host
    directory regression Commit fc663711b944 (scsi: core: Remove the /proc/scsi/${proc_name} directory
    earlier) fixed a bug related to modules loading/unloading, by adding a call to scsi_proc_hostdir_rm() on
    scsi_remove_host(). But that led to a potential duplicate call to the hostdir_rm() routine, since it's
    also called from scsi_host_dev_release(). That triggered a regression report, which was then fixed by
    commit be03df3d4bfe (scsi: core: Fix a procfs host directory removal regression). The fix just dropped
    the hostdir_rm() call from dev_release(). But it happens that this proc directory is created on
    scsi_host_alloc(), and that function pairs with scsi_host_dev_release(), while scsi_remove_host() pairs
    with scsi_add_host(). In other words, it seems the reason for removing the proc directory on dev_release()
    was meant to cover cases in which a SCSI host structure was allocated, but the call to scsi_add_host()
    didn't happen. And that pattern happens to exist in some error paths, for example. Syzkaller causes that
    by using USB raw gadget device, error'ing on usb-storage driver, at usb_stor_probe2(). By checking that
    path, we can see that the BadDevice label leads to a scsi_host_put() after a SCSI host allocation, but
    there's no call to scsi_add_host() in such path. That leads to messages like this in dmesg (and a leak of
    the SCSI host proc structure): usb-storage 4-1:87.51: USB Mass Storage device detected proc_dir_entry
    'scsi/usb-storage' already registered WARNING: CPU: 1 PID: 3519 at fs/proc/generic.c:377
    proc_register+0x347/0x4e0 fs/proc/generic.c:376 The proper fix seems to still call scsi_proc_hostdir_rm()
    on dev_release(), but guard that with the state check for SHOST_CREATED; there is even a comment in
    scsi_host_dev_release() detailing that: such conditional is meant for cases where the SCSI host was
    allocated but there was no calls to {add,remove}_host(), like the usb-storage case. This is what we
    propose here and with that, the error path of usb-storage does not trigger the warning anymore.
    (CVE-2024-26935)

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-2024-26935");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages.");
  script_set_cvss_base_vector("CVSS2#AV:L/AC:L/Au:S/C:N/I:N/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:N/I:N/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-2024-26935");

  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:"2024/04/09");
  script_set_attribute(attribute:"patch_publication_date", value:"2024/09/10");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/01/22");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:microsoft:azure_linux:hyperv-daemons");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:microsoft:azure_linux:hyperv-daemons-debuginfo");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:microsoft:azure_linux:hyperv-daemons-license");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:microsoft:azure_linux:hyperv-tools");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:microsoft:azure_linux:hypervfcopyd");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:microsoft:azure_linux:hypervkvpd");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:microsoft:azure_linux:hypervvssd");
  script_set_attribute(attribute:"cpe", value:"x-cpe:/o:microsoft:azure_linux");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Azure Linux 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/local_checks_enabled", "Host/AzureLinux/release", "Host/AzureLinux/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/AzureLinux/release');
if (isnull(release) || 'Azure Linux' >!< release) audit(AUDIT_OS_NOT, 'Azure Linux');
var os_ver = pregmatch(pattern: "Azure Linux ([0-9]+(\.[0-9]+)?)", string:release);
if (isnull(os_ver)) audit(AUDIT_UNKNOWN_APP_VER, 'Azure Linux');
os_ver = os_ver[1];
if (! preg(pattern:"^3([^0-9]|$)", string:os_ver)) audit(AUDIT_OS_NOT, 'Azure Linux 3.0', 'Azure Linux ' + os_ver);

if (!get_kb_item('Host/AzureLinux/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, 'Azure Linux', cpu);

var pkgs = [
    {'reference':'hyperv-daemons-6.6.35.1-1.azl3', 'cpu':'aarch64', 'release':'3.0', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'hyperv-daemons-6.6.35.1-1.azl3', 'cpu':'x86_64', 'release':'3.0', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'hyperv-daemons-debuginfo-6.6.35.1-1.azl3', 'cpu':'aarch64', 'release':'3.0', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'hyperv-daemons-debuginfo-6.6.35.1-1.azl3', 'cpu':'x86_64', 'release':'3.0', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'hyperv-daemons-license-6.6.35.1-1.azl3', 'release':'3.0', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'hyperv-daemons-license-6.6.35.1-1.azl3', 'release':'3.0', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'hyperv-tools-6.6.35.1-1.azl3', 'release':'3.0', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'hyperv-tools-6.6.35.1-1.azl3', 'release':'3.0', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'hypervfcopyd-6.6.35.1-1.azl3', 'cpu':'aarch64', 'release':'3.0', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'hypervfcopyd-6.6.35.1-1.azl3', 'cpu':'x86_64', 'release':'3.0', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'hypervkvpd-6.6.35.1-1.azl3', 'cpu':'aarch64', 'release':'3.0', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'hypervkvpd-6.6.35.1-1.azl3', 'cpu':'x86_64', 'release':'3.0', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'hypervvssd-6.6.35.1-1.azl3', 'cpu':'aarch64', 'release':'3.0', 'rpm_spec_vers_cmp':TRUE},
    {'reference':'hypervvssd-6.6.35.1-1.azl3', 'cpu':'x86_64', 'release':'3.0', '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 = 'Azure Linux ' + 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, 'hyperv-daemons / hyperv-daemons-debuginfo / hyperv-daemons-license / etc');
}

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22 Jan 2026 00:00Current
6.5Medium risk
Vulners AI Score6.5
CVSS 3.15.5
EPSS0.00244
SSVC
3