TencentOS Server 4: iscsi-initiator-utils (TSSA-2026:0983)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Tencent Linux Security Advisory TSSA-2026:0983.
##

include('compat.inc');

if (description)
{
  script_id(344407);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/09/09");

  script_cve_id("CVE-2026-18726", "CVE-2026-18727", "CVE-2026-18728");

  script_name(english:"TencentOS Server 4: iscsi-initiator-utils (TSSA-2026:0983)");

  script_set_attribute(attribute:"synopsis", value:
"The remote TencentOS Server 4 host is missing one or more security updates.");
  script_set_attribute(attribute:"description", value:
"The version of Tencent Linux installed on the remote TencentOS Server 4 host is prior to tested version. It is,
therefore, affected by multiple vulnerabilities as referenced in the TSSA-2026:0983 advisory.

    Package updates are available for TencentOS Server 4 that fix the following vulnerabilities:

    CVE-2026-18728:
    A flaw was found in open-iscsi. An integer underflow vulnerability in the iscsiuio component, specifically
    during IPv4 Dynamic Host Configuration Protocol (DHCP) parsing, allows a remote attacker on the same local
    network segment to cause a denial of service. By sending a specially crafted IPv4/UDP DHCP reply, the
    attacker can trigger an out-of-bounds read, leading to the iscsiuio process crashing. This issue affects
    systems where iscsiuio is actively handling IPv4 DHCP traffic.

    CVE-2026-18727:
    A flaw was found in open-iscsi's iscsiuio component. This vulnerability involves an integer underflow and
    out-of-bounds read during Dynamic Host Configuration Protocol for IPv6 (DHCPv6) packet parsing.
    Specifically, crafted DHCPv6 Advertise traffic with a short User Datagram Protocol (UDP) length can cause
    the DHCPv6 payload length to underflow. An unauthenticated attacker on an adjacent network segment can
    exploit this by sending specially crafted IPv6 UDP traffic while the client is in an active DHCPv6
    exchange, leading to a denial of service due to a process crash or service disruption.

    CVE-2026-18726:
    A flaw was found in open-iscsi. This vulnerability allows a remote attacker on the same local network
    segment to cause a Denial of Service (DoS) in the iscsiuio daemon. By sending a specially crafted ICMPv6
    Router Advertisement with a zero-length option, the attacker can trigger an infinite loop, leading to
    sustained CPU usage and rendering the daemon unresponsive. A secondary risk of out-of-bounds reads exists
    with a short IPv6 payload.

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

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version
number.");
  script_set_attribute(attribute:"see_also", value:"https://mirrors.tencent.com/tlinux/errata/tssa-20260983.xml");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages.");
  script_set_cvss_base_vector("CVSS2#AV:A/AC:L/Au:N/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:A/AC:L/PR:N/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-2026-18728");

  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:"2026/08/12");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/09/07");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/09/09");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:tencent:tencentos_server:4");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:tencent:tencentos_server:iscsi-initiator-utils");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Tencent 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/etc/os-release", "Host/TencentOS/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) || 'TencentOS' >!< os_product) audit(AUDIT_OS_NOT, 'TencentOS');
var os_version = get_kb_item('installed_os/local/SSH/0/version');
if (isnull(os_version)) audit(AUDIT_UNKNOWN_APP_VER, 'TencentOS');
if (! preg(pattern:"^4([^0-9]|$)", string:os_version)) audit(AUDIT_OS_NOT, 'TencentOS 4.x', 'TencentOS ' + os_version);

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

var cpu = get_kb_item('Host/cpu');
if (isnull(cpu)) audit(AUDIT_UNKNOWN_ARCH);
if ('x86_64' >!< cpu && cpu !~ "^i[3-6]86$" && 's390' >!< cpu && 'aarch64' >!< cpu) audit(AUDIT_LOCAL_CHECKS_NOT_IMPLEMENTED, 'TencentOS', cpu);

var constraints = [
  {
    'release': '4',
    'pkgs': [
      {'reference':'iscsi-initiator-utils-6.2.1.9-4.gita65a472.tl4', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'iscsi-initiator-utils-6.2.1.9-4.gita65a472.tl4', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'iscsi-initiator-utils-debuginfo-6.2.1.9-4.gita65a472.tl4', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'iscsi-initiator-utils-debuginfo-6.2.1.9-4.gita65a472.tl4', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'iscsi-initiator-utils-debugsource-6.2.1.9-4.gita65a472.tl4', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'iscsi-initiator-utils-debugsource-6.2.1.9-4.gita65a472.tl4', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'iscsi-initiator-utils-devel-6.2.1.9-4.gita65a472.tl4', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'iscsi-initiator-utils-devel-6.2.1.9-4.gita65a472.tl4', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'iscsi-initiator-utils-iscsiuio-6.2.1.9-4.gita65a472.tl4', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'iscsi-initiator-utils-iscsiuio-6.2.1.9-4.gita65a472.tl4', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'iscsi-initiator-utils-iscsiuio-debuginfo-6.2.1.9-4.gita65a472.tl4', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'iscsi-initiator-utils-iscsiuio-debuginfo-6.2.1.9-4.gita65a472.tl4', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'python3-iscsi-initiator-utils-6.2.1.9-4.gita65a472.tl4', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'python3-iscsi-initiator-utils-6.2.1.9-4.gita65a472.tl4', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'python3-iscsi-initiator-utils-debuginfo-6.2.1.9-4.gita65a472.tl4', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'python3-iscsi-initiator-utils-debuginfo-6.2.1.9-4.gita65a472.tl4', '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, 'iscsi-initiator-utils / iscsi-initiator-utils-debuginfo / iscsi-initiator-utils-debugsource / etc');
}