TencentOS Server 3: tigervnc (TSSA-2024:0248)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Tencent Linux Security Advisory TSSA-2024:0248.
##

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

if (description)
{
  script_id(239888);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2025/11/20");

  script_cve_id("CVE-2024-31080", "CVE-2024-31081", "CVE-2024-31083");

  script_name(english:"TencentOS Server 3: tigervnc (TSSA-2024:0248)");

  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-2024:0248 advisory.

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

    CVE-2024-31080:
    A heap-based buffer over-read vulnerability was found in the X.org server's ProcXIGetSelectedEvents()
    function. This issue occurs when byte-swapped length values are used in replies, potentially leading to
    memory leakage and segmentation faults, particularly when triggered by a client with a different
    endianness. This vulnerability could be exploited by an attacker to cause the X server to read heap memory
    values and then transmit them back to the client until encountering an unmapped page, resulting in a
    crash. Despite the attacker's inability to control the specific memory copied into the replies, the small
    length values typically stored in a 32-bit integer can result in significant attempted out-of-bounds
    reads.

    CVE-2024-31081:
    A heap-based buffer over-read vulnerability was found in the X.org server's ProcXIPassiveGrabDevice()
    function. This issue occurs when byte-swapped length values are used in replies, potentially leading to
    memory leakage and segmentation faults, particularly when triggered by a client with a different
    endianness. This vulnerability could be exploited by an attacker to cause the X server to read heap memory
    values and then transmit them back to the client until encountering an unmapped page, resulting in a
    crash. Despite the attacker's inability to control the specific memory copied into the replies, the small
    length values typically stored in a 32-bit integer can result in significant attempted out-of-bounds
    reads.

    CVE-2024-31083:
    A use-after-free vulnerability was found in the ProcRenderAddGlyphs() function of Xorg servers. This issue
    occurs when AllocateGlyph() is called to store new glyphs sent by the client to the X server, potentially
    resulting in multiple entries pointing to the same non-refcounted glyphs. Consequently,
    ProcRenderAddGlyphs() may free a glyph, leading to a use-after-free scenario when the same glyph pointer
    is subsequently accessed. This flaw allows an authenticated attacker to execute arbitrary code on the
    system by sending a specially crafted request.

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-20240248.xml");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:S/C:P/I:P/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:H/I:H/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-2024-31081");
  script_set_attribute(attribute:"cvss3_score_source", value:"CVE-2024-31083");

  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:"2024/04/24");
  script_set_attribute(attribute:"patch_publication_date", value:"2024/04/24");
  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:tigervnc");
  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':'tigervnc-1.13.1-2.tl3.10', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'tigervnc-1.13.1-2.tl3.10', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'tigervnc-debuginfo-1.13.1-2.tl3.10', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'tigervnc-debuginfo-1.13.1-2.tl3.10', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'tigervnc-debugsource-1.13.1-2.tl3.10', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'tigervnc-debugsource-1.13.1-2.tl3.10', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'tigervnc-icons-1.13.1-2.tl3.10', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'tigervnc-license-1.13.1-2.tl3.10', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'tigervnc-selinux-1.13.1-2.tl3.10', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'tigervnc-server-1.13.1-2.tl3.10', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'tigervnc-server-1.13.1-2.tl3.10', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'tigervnc-server-debuginfo-1.13.1-2.tl3.10', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'tigervnc-server-debuginfo-1.13.1-2.tl3.10', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'tigervnc-server-minimal-1.13.1-2.tl3.10', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'tigervnc-server-minimal-1.13.1-2.tl3.10', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'tigervnc-server-minimal-debuginfo-1.13.1-2.tl3.10', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'tigervnc-server-minimal-debuginfo-1.13.1-2.tl3.10', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'tigervnc-server-module-1.13.1-2.tl3.10', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'tigervnc-server-module-1.13.1-2.tl3.10', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'tigervnc-server-module-debuginfo-1.13.1-2.tl3.10', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'tigervnc-server-module-debuginfo-1.13.1-2.tl3.10', '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_HOLE,
      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, 'tigervnc / tigervnc-debuginfo / tigervnc-debugsource / etc');
}