Unity Linux 20.1050a Security Update: kernel (UTSA-2026-006993)

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

include('compat.inc');

if (description)
{
  script_id(308333);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/04/21");

  script_cve_id("CVE-2025-39824");

  script_name(english:"Unity Linux 20.1050a Security Update: kernel (UTSA-2026-006993)");

  script_set_attribute(attribute:"synopsis", value:
"The Unity Linux host is missing one or more security updates.");
  script_set_attribute(attribute:"description", value:
"The Unity Linux 20 host has a package installed that is affected by a vulnerability as referenced in the
UTSA-2026-006993 advisory.

    In the Linux kernel, the following vulnerability has been resolved:

    HID: asus: fix UAF via HID_CLAIMED_INPUT validation

    After hid_hw_start() is called hidinput_connect() will eventually be
    called to set up the device with the input layer since the
    HID_CONNECT_DEFAULT connect mask is used. During hidinput_connect()
    all input and output reports are processed and corresponding hid_inputs
    are allocated and configured via hidinput_configure_usages(). This
    process involves slot tagging report fields and configuring usages
    by setting relevant bits in the capability bitmaps. However it is possible
    that the capability bitmaps are not set at all leading to the subsequent
    hidinput_has_been_populated() check to fail leading to the freeing of the
    hid_input and the underlying input device.

    This becomes problematic because a malicious HID device like a
    ASUS ROG N-Key keyboard can trigger the above scenario via a
    specially crafted descriptor which then leads to a user-after-free
    when the name of the freed input device is written to later on after
    hid_hw_start(). Below, report 93 intentionally utilises the
    HID_UP_UNDEFINED Usage Page which is skipped during usage
    configuration, leading to the frees.

    0x05, 0x0D,        // Usage Page (Digitizer)
    0x09, 0x05,        // Usage (Touch Pad)
    0xA1, 0x01,        // Collection (Application)
    0x85, 0x0D,        //   Report ID (13)
    0x06, 0x00, 0xFF,  //   Usage Page (Vendor Defined 0xFF00)
    0x09, 0xC5,        //   Usage (0xC5)
    0x15, 0x00,        //   Logical Minimum (0)
    0x26, 0xFF, 0x00,  //   Logical Maximum (255)
    0x75, 0x08,        //   Report Size (8)
    0x95, 0x04,        //   Report Count (4)
    0xB1, 0x02,        //   Feature (Data,Var,Abs)
    0x85, 0x5D,        //   Report ID (93)
    0x06, 0x00, 0x00,  //   Usage Page (Undefined)
    0x09, 0x01,        //   Usage (0x01)
    0x15, 0x00,        //   Logical Minimum (0)
    0x26, 0xFF, 0x00,  //   Logical Maximum (255)
    0x75, 0x08,        //   Report Size (8)
    0x95, 0x1B,        //   Report Count (27)
    0x81, 0x02,        //   Input (Data,Var,Abs)
    0xC0,              // End Collection

    Below is the KASAN splat after triggering the UAF:

    [   21.672709] ==================================================================
    [   21.673700] BUG: KASAN: slab-use-after-free in asus_probe+0xeeb/0xf80
    [   21.673700] Write of size 8 at addr ffff88810a0ac000 by task kworker/1:2/54
    [   21.673700]
    [   21.673700] CPU: 1 UID: 0 PID: 54 Comm: kworker/1:2 Not tainted 6.16.0-rc4-g9773391cf4dd-dirty #36
    PREEMPT(voluntary)
    [   21.673700] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1
    04/01/2014
    [   21.673700] Call Trace:
    [   21.673700]  <TASK>
    [   21.673700]  dump_stack_lvl+0x5f/0x80
    [   21.673700]  print_report+0xd1/0x660
    [   21.673700]  kasan_report+0xe5/0x120
    [   21.673700]  __asan_report_store8_noabort+0x1b/0x30
    [   21.673700]  asus_probe+0xeeb/0xf80
    [   21.673700]  hid_device_probe+0x2ee/0x700
    [   21.673700]  really_probe+0x1c6/0x6b0
    [   21.673700]  __driver_probe_device+0x24f/0x310
    [   21.673700]  driver_probe_device+0x4e/0x220
    [...]
    [   21.673700]
    [   21.673700] Allocated by task 54:
    [   21.673700]  kasan_save_stack+0x3d/0x60
    [   21.673700]  kasan_save_track+0x18/0x40
    [   21.673700]  kasan_save_alloc_info+0x3b/0x50
    [   21.673700]  __kasan_kmalloc+0x9c/0xa0
    [   21.673700]  __kmalloc_cache_noprof+0x139/0x340
    [   21.673700]  input_allocate_device+0x44/0x370
    [   21.673700]  hidinput_connect+0xcb6/0x2630
    [   21.673700]  hid_connect+0xf74/0x1d60
    [   21.673700]  hid_hw_start+0x8c/0x110
    [   21.673700]  asus_probe+0x5a3/0xf80
    [   21.673700]  hid_device_probe+0x2ee/0x700
    [   21.673700]  really_probe+0x1c6/0x6b0
    [   21.673700]  __driver_probe_device+0x24f/0x310
    [   21.673700]  driver_probe_device+0x4e/0x220
    [...]
    [   21.673700]
    [   21.673700] Freed by task 54:
    [   21.673700]  kasan_save_stack+0x3d/0x60
    [   21.673700]  kasan_save_track+0x18/0x40
    [   21.673700]  kasan_save_free_info+0x3f/0x60
    [   21.673700]  __kasan_slab_free+0x3c/0x50
    [   21.673700]  kfre
    ---truncated---

Tenable has extracted the preceding description block directly from the Unity Linux security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version
number.");
  # https://src.uniontech.com/#/security_advisory_detail?utsa_id=UTSA-2026-006993
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?f8215393");
  # https://lore.kernel.org/linux-cve-announce/2025091616-CVE-2025-39824-6491@gregkh
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?8cdd36e3");
  script_set_attribute(attribute:"see_also", value:"https://nvd.nist.gov/vuln/detail/CVE-2025-39824");
  script_set_attribute(attribute:"solution", value:
"Update the affected kernel package.");
  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-2025-39824");

  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:"2025/09/16");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/04/08");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/04/21");

  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:"Unity 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/UOS-Server/release", "Host/UOS-Server/rpm-list", "Host/cpu");

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

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) || 'UOS Server' >!< os_product) audit(AUDIT_OS_NOT, 'UOS Server');
var os_version = get_kb_item('installed_os/local/SSH/0/version');
if (isnull(os_version)) audit(AUDIT_UNKNOWN_APP_VER, 'UOS Server');
if (! preg(pattern:"^20.1050a([^0-9]|$)", string:os_version)) audit(AUDIT_OS_NOT, 'UOS Server 20.1050a', 'UOS Server ' + os_version);

if (!get_kb_item('Host/UOS-Server/rpm-list')) audit(AUDIT_PACKAGE_LIST_MISSING);

var cpu = get_kb_item('Host/cpu');
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ('aarch64' >!< cpu && 'amd64' >!< cpu && 'x86_64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'UOS Server', cpu);


var constraints = [
  {
    'release': '20',
    'sp': '1050a',
    'pkgs': [
      {'reference':'kernel-5.10.0-27.5', 'sp':'1050a', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-5.10.0-27.5', 'sp':'1050a', 'cpu':'amd64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-5.10.0-27.5', 'sp':'1050a', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE}
    ]
  }
];

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_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, 'kernel');
}