Unity Linux 20.1050e Security Update: kernel (UTSA-2026-102108)

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

include('compat.inc');

if (description)
{
  script_id(338582);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/08/21");

  script_cve_id("CVE-2025-71160");

  script_name(english:"Unity Linux 20.1050e Security Update: kernel (UTSA-2026-102108)");

  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-2026-102108 advisory.

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

    netfilter: nf_tables: avoid chain re-validation if possible

    Hamza Mahfooz reports cpu soft lock-ups in
    nft_chain_validate():

     watchdog: BUG: soft lockup - CPU#1 stuck for 27s! [iptables-nft-re:37547]
    [..]
     RIP: 0010:nft_chain_validate+0xcb/0x110 [nf_tables]
    [..]
      nft_immediate_validate+0x36/0x50 [nf_tables]
      nft_chain_validate+0xc9/0x110 [nf_tables]
      nft_immediate_validate+0x36/0x50 [nf_tables]
      nft_chain_validate+0xc9/0x110 [nf_tables]
      nft_immediate_validate+0x36/0x50 [nf_tables]
      nft_chain_validate+0xc9/0x110 [nf_tables]
      nft_immediate_validate+0x36/0x50 [nf_tables]
      nft_chain_validate+0xc9/0x110 [nf_tables]
      nft_immediate_validate+0x36/0x50 [nf_tables]
      nft_chain_validate+0xc9/0x110 [nf_tables]
      nft_immediate_validate+0x36/0x50 [nf_tables]
      nft_chain_validate+0xc9/0x110 [nf_tables]
      nft_table_validate+0x6b/0xb0 [nf_tables]
      nf_tables_validate+0x8b/0xa0 [nf_tables]
      nf_tables_commit+0x1df/0x1eb0 [nf_tables]
    [..]

    Currently nf_tables will traverse the entire table (chain graph), starting
    from the entry points (base chains), exploring all possible paths
    (chain jumps).  But there are cases where we could avoid revalidation.

    Consider:
    1  input -> j2 -> j3
    2  input -> j2 -> j3
    3  input -> j1 -> j2 -> j3

    Then the second rule does not need to revalidate j2, and, by extension j3,
    because this was already checked during validation of the first rule.
    We need to validate it only for rule 3.

    This is needed because chain loop detection also ensures we do not exceed
    the jump stack: Just because we know that j2 is cycle free, its last jump
    might now exceed the allowed stack size.  We also need to update all
    reachable chains with the new largest observed call depth.

    Care has to be taken to revalidate even if the chain depth won't be an
    issue: chain validation also ensures that expressions are not called from
    invalid base chains.  For example, the masquerade expression can only be
    called from NAT postrouting base chains.

    Therefore we also need to keep record of the base chain context (type,
    hooknum) and revalidate if the chain becomes reachable from a different
    hook location.

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-2026-102108
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?9128db84");
  # https://git.kernel.org/stable/c/09d6074995c186e449979fe6c1b0f1a69cf9bd3b
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?10026fd5");
  # https://git.kernel.org/stable/c/14fa3d1927f1382f86e3f70a51f26005c8e3cff6
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?49aabff6");
  # https://git.kernel.org/stable/c/53de1e6cde8f9b791d9cf61aa0e7b02cf5bbe8b1
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?c420081f");
  # https://git.kernel.org/stable/c/8e1a1bc4f5a42747c08130b8242ebebd1210b32f
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?d7c1b651");
  # https://lore.kernel.org/linux-cve-announce/2026012346-CVE-2025-71160-8c5d@gregkh
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?d447a125");
  script_set_attribute(attribute:"see_also", value:"https://nvd.nist.gov/vuln/detail/CVE-2025-71160");
  script_set_attribute(attribute:"see_also", value:"https://security-tracker.debian.org/tracker/CVE-2025-71160");
  script_set_attribute(attribute:"solution", value:
"Update the affected kernel package.");
  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-2025-71160");

  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:"2026/01/23");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/08/17");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/08/21");

  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:"^(20.1050e)([^0-9]|$)", string:os_version)) audit(AUDIT_OS_NOT, 'UOS Server 20.1050e', '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': '1050e',
    'pkgs': [
      {'reference':'kernel-4.19.90-2211.5.0.0178.67.uel20', 'sp':'1050e', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-4.19.90-2211.5.0.0178.67.uel20', 'sp':'1050e', 'cpu':'amd64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-4.19.90-2211.5.0.0178.67.uel20', 'sp':'1050e', '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');
}