TencentOS Server 3: dhcp (TSSA-2023:0087)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Tencent Linux Security Advisory TSSA-2023:0087.
##

include('deprecated_nasl_level.inc');
include('compat.inc');

if (description)
{
  script_id(238727);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2025/11/20");

  script_cve_id("CVE-2022-2928", "CVE-2022-2929");

  script_name(english:"TencentOS Server 3: dhcp (TSSA-2023:0087)");

  script_set_attribute(attribute:"synopsis", value:
"The remote TencentOS Server 3 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 3 host is prior to tested version. It is,
therefore, affected by multiple vulnerabilities as referenced in the TSSA-2023:0087 advisory.

    Package updates are available for TencentOS Server 3 that fix the following vulnerabilities:

      CVE-2022-2928:
      An integer overflow vulnerability was found in the DHCP server. When the option_code_hash_lookup()
    function is called from add_option(), it increases the option's refcount field. However, there is not
    a corresponding call to option_dereference() to decrement the refcount field. The add_option()
    function is only used in server responses to lease query packets. Each lease query response calls this
    function for several options. Hence, a DHCP server configured with allow lease query, a remote machine
    with access to the server, can send lease queries for the same lease multiple times, leading to the
    add_option() function being called repeatedly. This issue could cause the reference counters to overflow
    and the server to abort or crash.
      CVE-2022-2929:
      A vulnerability was found in the DHCP server where the fqdn_universe_decode() function allocates
    buffer space for the contents of option 81 (fqdn) data received in a DHCP packet. The maximum length of a
    DNS label is 63 bytes. The function tests the length byte of each label contained in the fqdn; if it
    finds a label whose length byte value is larger than 63, it returns without dereferencing the buffer
    space. This issue causes a memory leak. On a system with access to a DHCP server, an attacker from any
    adjacent network could send DHCP packets crafted to include fqdn labels longer than 63 bytes to the DHCP
    server, eventually causing the server to run out of memory and crash.

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-20230087.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-2022-2929");

  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:"2023/06/14");
  script_set_attribute(attribute:"patch_publication_date", value:"2023/06/14");
  script_set_attribute(attribute:"plugin_publication_date", value:"2025/06/16");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:tencent:tencentos_server:3");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:tencent:tencentos_server:dhcp");
  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) 2025 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:"^3([^0-9]|$)", string:os_version)) audit(AUDIT_OS_NOT, 'TencentOS 3.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': '3',
    'pkgs': [
      {'reference':'dhcp-client-4.3.6-49.tl3', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'dhcp-client-4.3.6-49.tl3', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'dhcp-client-debuginfo-4.3.6-49.tl3', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'dhcp-client-debuginfo-4.3.6-49.tl3', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'dhcp-common-4.3.6-49.tl3', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'dhcp-debuginfo-4.3.6-49.tl3', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'dhcp-debuginfo-4.3.6-49.tl3', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'dhcp-debugsource-4.3.6-49.tl3', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'dhcp-debugsource-4.3.6-49.tl3', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'dhcp-devel-4.3.6-49.tl3', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'dhcp-devel-4.3.6-49.tl3', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'dhcp-devel-doc-4.3.6-49.tl3', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'dhcp-libs-4.3.6-49.tl3', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'dhcp-libs-4.3.6-49.tl3', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'dhcp-libs-debuginfo-4.3.6-49.tl3', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'dhcp-libs-debuginfo-4.3.6-49.tl3', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'dhcp-relay-4.3.6-49.tl3', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'dhcp-relay-4.3.6-49.tl3', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'dhcp-relay-debuginfo-4.3.6-49.tl3', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'dhcp-relay-debuginfo-4.3.6-49.tl3', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'dhcp-server-4.3.6-49.tl3', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'dhcp-server-4.3.6-49.tl3', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'dhcp-server-debuginfo-4.3.6-49.tl3', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'dhcp-server-debuginfo-4.3.6-49.tl3', '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, 'dhcp-client / dhcp-client-debuginfo / dhcp-common / etc');
}