Unity Linux 20.1070a Security Update: kernel (UTSA-2026-013055)

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

include('compat.inc');

if (description)
{
  script_id(307774);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/04/21");

  script_cve_id("CVE-2023-53853");

  script_name(english:"Unity Linux 20.1070a Security Update: kernel (UTSA-2026-013055)");

  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-2026-013055 advisory.

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

    netlink: annotate accesses to nlk->cb_running

    Both netlink_recvmsg() and netlink_native_seq_show() read
    nlk->cb_running locklessly. Use READ_ONCE() there.

    Add corresponding WRITE_ONCE() to netlink_dump() and
    __netlink_dump_start()

    syzbot reported:
    BUG: KCSAN: data-race in __netlink_dump_start / netlink_recvmsg

    write to 0xffff88813ea4db59 of 1 bytes by task 28219 on cpu 0:
    __netlink_dump_start+0x3af/0x4d0 net/netlink/af_netlink.c:2399
    netlink_dump_start include/linux/netlink.h:308 [inline]
    rtnetlink_rcv_msg+0x70f/0x8c0 net/core/rtnetlink.c:6130
    netlink_rcv_skb+0x126/0x220 net/netlink/af_netlink.c:2577
    rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:6192
    netlink_unicast_kernel net/netlink/af_netlink.c:1339 [inline]
    netlink_unicast+0x56f/0x640 net/netlink/af_netlink.c:1365
    netlink_sendmsg+0x665/0x770 net/netlink/af_netlink.c:1942
    sock_sendmsg_nosec net/socket.c:724 [inline]
    sock_sendmsg net/socket.c:747 [inline]
    sock_write_iter+0x1aa/0x230 net/socket.c:1138
    call_write_iter include/linux/fs.h:1851 [inline]
    new_sync_write fs/read_write.c:491 [inline]
    vfs_write+0x463/0x760 fs/read_write.c:584
    ksys_write+0xeb/0x1a0 fs/read_write.c:637
    __do_sys_write fs/read_write.c:649 [inline]
    __se_sys_write fs/read_write.c:646 [inline]
    __x64_sys_write+0x42/0x50 fs/read_write.c:646
    do_syscall_x64 arch/x86/entry/common.c:50 [inline]
    do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
    entry_SYSCALL_64_after_hwframe+0x63/0xcd

    read to 0xffff88813ea4db59 of 1 bytes by task 28222 on cpu 1:
    netlink_recvmsg+0x3b4/0x730 net/netlink/af_netlink.c:2022
    sock_recvmsg_nosec+0x4c/0x80 net/socket.c:1017
    ____sys_recvmsg+0x2db/0x310 net/socket.c:2718
    ___sys_recvmsg net/socket.c:2762 [inline]
    do_recvmmsg+0x2e5/0x710 net/socket.c:2856
    __sys_recvmmsg net/socket.c:2935 [inline]
    __do_sys_recvmmsg net/socket.c:2958 [inline]
    __se_sys_recvmmsg net/socket.c:2951 [inline]
    __x64_sys_recvmmsg+0xe2/0x160 net/socket.c:2951
    do_syscall_x64 arch/x86/entry/common.c:50 [inline]
    do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
    entry_SYSCALL_64_after_hwframe+0x63/0xcd

    value changed: 0x00 -> 0x01

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-2026-013055
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?18a85590");
  # https://lore.kernel.org/linux-cve-announce/2025120902-CVE-2023-53853-424f@gregkh
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?f81cedd7");
  script_set_attribute(attribute:"see_also", value:"https://nvd.nist.gov/vuln/detail/CVE-2023-53853");
  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-2023-53853");

  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:"2021/07/21");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/04/21");
  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:"^20.1070a([^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 && 'x86_64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'UOS Server', cpu);


var constraints = [
  {
    'release': '20',
    'sp': '1070a',
    'pkgs': [
      {'reference':'kernel-5.10.0-79.10', 'sp':'1070a', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-5.10.0-79.10', 'sp':'1070a', 'cpu':'amd64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'kernel-5.10.0-79.10', '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_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');
}