Unity Linux 20.1050a Security Update: kernel (UTSA-2026-098964)

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

include('compat.inc');

if (description)
{
  script_id(340386);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/08/28");

  script_cve_id("CVE-2025-71098");

  script_name(english:"Unity Linux 20.1050a Security Update: kernel (UTSA-2026-098964)");

  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-2026-098964 advisory.

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

    ip6_gre: make ip6gre_header() robust

    Over the years, syzbot found many ways to crash the kernel
    in ip6gre_header() [1].

    This involves team or bonding drivers ability to dynamically
    change their dev->needed_headroom and/or dev->hard_header_len

    In this particular crash mld_newpack() allocated an skb
    with a too small reserve/headroom, and by the time mld_sendpack()
    was called, syzbot managed to attach an ip6gre device.

    [1]
    skbuff: skb_under_panic: text:ffffffff8a1d69a8 len:136 put:40 head:ffff888059bc7000 data:ffff888059bc6fe8
    tail:0x70 end:0x6c0 dev:team0
    ------------[ cut here ]------------
     kernel BUG at net/core/skbuff.c:213 !
     <TASK>
      skb_under_panic net/core/skbuff.c:223 [inline]
      skb_push+0xc3/0xe0 net/core/skbuff.c:2641
      ip6gre_header+0xc8/0x790 net/ipv6/ip6_gre.c:1371
      dev_hard_header include/linux/netdevice.h:3436 [inline]
      neigh_connected_output+0x286/0x460 net/core/neighbour.c:1618
      neigh_output include/net/neighbour.h:556 [inline]
      ip6_finish_output2+0xfb3/0x1480 net/ipv6/ip6_output.c:136
     __ip6_finish_output net/ipv6/ip6_output.c:-1 [inline]
      ip6_finish_output+0x234/0x7d0 net/ipv6/ip6_output.c:220
      NF_HOOK_COND include/linux/netfilter.h:307 [inline]
      ip6_output+0x340/0x550 net/ipv6/ip6_output.c:247
      NF_HOOK+0x9e/0x380 include/linux/netfilter.h:318
      mld_sendpack+0x8d4/0xe60 net/ipv6/mcast.c:1855
      mld_send_cr net/ipv6/mcast.c:2154 [inline]
      mld_ifc_work+0x83e/0xd60 net/ipv6/mcast.c:2693

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-2026-098964
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?87397911");
  # https://lore.kernel.org/linux-cve-announce/2026011344-CVE-2025-71098-ef6d@gregkh
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?b57e9054");
  script_set_attribute(attribute:"see_also", value:"https://nvd.nist.gov/vuln/detail/CVE-2025-71098");
  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-2025-71098");

  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:"2026/01/13");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/08/10");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/08/26");

  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 && 'loongarch64' >!< cpu && 'x86_64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'UOS Server', cpu);


var constraints = [
  {
    'release': '20',
    'sp': '1050a',
    'pkgs': [
      {'reference':'kernel-4.19.0-91.82.132.24.uelc20', 'sp':'1050a', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-4.19.0-91.82.132.24.uelc20', 'sp':'1050a', 'cpu':'amd64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-4.19.0-91.82.132.24.uelc20', 'sp':'1050a', 'cpu':'loongarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-4.19.0-91.82.132.24.uelc20', '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');
}