Unity Linux 20.1070a Security Update: kernel (UTSA-2026-143106)

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

include('compat.inc');

if (description)
{
  script_id(370848);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/10/22");

  script_cve_id("CVE-2026-23455");

  script_name(english:"Unity Linux 20.1070a Security Update: kernel (UTSA-2026-143106)");

  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-2026-143106 advisory.

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

    netfilter: nf_conntrack_h323: check for zero length in DecodeQ931()

    In DecodeQ931(), the UserUserIE code path reads a 16-bit length from
    the packet, then decrements it by 1 to skip the protocol discriminator
    byte before passing it to DecodeH323_UserInformation(). If the encoded
    length is 0, the decrement wraps to -1, which is then passed as a
    large value to the decoder, leading to an out-of-bounds read.

    Add a check to ensure len is positive after the decrement.

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-2026-143106
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?c8f90a16");
  script_set_attribute(attribute:"see_also", value:"https://cert-portal.siemens.com/productcert/html/ssa-019113.html");
  script_set_attribute(attribute:"see_also", value:"https://cert-portal.siemens.com/productcert/html/ssa-082556.html");
  # https://git.kernel.org/stable/c/2121f5fbe88daff0f1fc5bc47d359426c74b86b0
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?591903df");
  # https://git.kernel.org/stable/c/495e97af9e7249ee02b72bb1d0848a6efc3700f4
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?ef880a20");
  # https://git.kernel.org/stable/c/633e8f87dad32263f6a57dccdb873f042c062111
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?ee1578ac");
  # https://git.kernel.org/stable/c/65fa92f79677858b14b9e4b7275f26639afe2710
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?b74c5dfc");
  # https://git.kernel.org/stable/c/9d00fe7d6d7c5b5f1065a6e042b54f2e44bd6df8
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?2c59a474");
  # https://git.kernel.org/stable/c/b652b05d51003ac074b912684f9ec7486231717b
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?f2c0fadf");
  # https://git.kernel.org/stable/c/f173d0f4c0f689173f8cdac79991043a4a89bf66
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?d61c57c5");
  # https://git.kernel.org/stable/c/f5e4f4e4cdb75ec36802059a94195a31f193da60
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?4e3f6bf4");
  # https://lore.kernel.org/linux-cve-announce/2026040317-CVE-2026-23455-f045@gregkh
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?97314665");
  script_set_attribute(attribute:"see_also", value:"https://nvd.nist.gov/vuln/detail/CVE-2026-23455");
  script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2026-23455");
  script_set_attribute(attribute:"solution", value:
"Update the affected kernel package.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:C/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:N/AC:L/PR:N/UI:N/S:U/C:H/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-2026-23455");

  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:"2026/04/03");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/10/23");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/10/22");

  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:"^(20.1070a)([^0-9]|$)", string:os_version)) audit(AUDIT_OS_NOT, 'UOS Server 20.1070a', '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 && 'loongarch64' >!< cpu && 'x86_64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'UOS Server', cpu);


var constraints = [
  {
    'release': '20',
    'sp': '1070a',
    'pkgs': [
      {'reference':'kernel-5.10.0-79.27.uelc20', 'sp':'1070a', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-5.10.0-79.27.uelc20', 'sp':'1070a', 'cpu':'amd64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-5.10.0-79.27.uelc20', 'sp':'1070a', 'cpu':'loongarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-5.10.0-79.27.uelc20', 'sp':'1070a', '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_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, 'kernel');
}