TencentOS Server 3: gstreamer1-plugins-good (TSSA-2026:1059)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Tencent Linux Security Advisory TSSA-2026:1059.
##

include('compat.inc');

if (description)
{
  script_id(349540);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/09/23");

  script_cve_id("CVE-2026-18649", "CVE-2026-73433", "CVE-2026-73434");

  script_name(english:"TencentOS Server 3: gstreamer1-plugins-good (TSSA-2026:1059)");

  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-2026:1059 advisory.

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

    CVE-2026-18649:
    A flaw was found in the GStreamer gst-plugins-good package. The rtph264depay and rtph265depay RTP
    depayloader elements do not enforce a maximum size limit on the reassembly buffer used during fragmented
    RTP packet processing. A remote, unauthenticated attacker can send a continuous stream of RTP fragments
    without ever transmitting an end-of-fragment marker, causing the reassembly buffer to grow without bound
    until process memory is exhausted. This results in a denial of service through process termination.

    CVE-2026-73433:
    A flaw was found in GStreamer gst-plugins-good (avidemux). When parsing FUJIFILM metadata in an AVI strd
    chunk, gst_avi_demux_parse_strd() decrements a remaining-length counter by fixed offsets (98 and 10 bytes)
    without verifying sufficient data remains. For crafted strd payloads of exactly 106 or 107 bytes, the
    counter underflows to a very large unsigned value, causing subsequent null-terminated string scanning to
    read far beyond the allocated heap buffer. Date-format normalization may also write beyond the buffer end.
    Confirmed impacts include heap out-of-bounds read, out-of-bounds write, heap information disclosure
    (adjacent data appearing in parsed metadata), and application crash/denial of service. The avidemux
    element is auto-plugged by playbin, decodebin, and gst-discoverer, so opening or previewing a crafted AVI
    is sufficient to trigger the issue. Fixed upstream in gst-plugins-good 1.28.6 (GStreamer-SA-2026-0072).

    CVE-2026-73434:
    A flaw was found in GStreamer gst-plugins-good (avidemux). In gst_avi_demux_riff_parse_vprp(), the number
    of available gst_riff_vprp_video_field_desc entries is calculated by dividing the remaining buffer size by
    the attacker-controlled vprp->fields value, rather than by sizeof(gst_riff_vprp_video_field_desc). This
    can cause the parser to treat more field descriptors as available than fit in the input buffer, resulting
    in out-of-bounds reads. Processing a crafted AVI via playbin/decodebin can crash the application (denial
    of service). Fixed upstream in gst-plugins-good 1.28.6 (GStreamer-SA-2026-0072).

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-20261059.xml");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:P/I:N/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:POC/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:P/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-73434");
  script_set_attribute(attribute:"cvss3_score_source", value:"CVE-2026-73433");

  script_set_attribute(attribute:"exploitability_ease", value:"Exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"true");

  script_set_attribute(attribute:"vuln_publication_date", value:"2026/08/06");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/08/19");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/09/23");

  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:gstreamer1-plugins-good");
  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:"^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':'gstreamer1-plugins-good-1.16.1-7.tl3.3', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'gstreamer1-plugins-good-1.16.1-7.tl3.3', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'gstreamer1-plugins-good-debuginfo-1.16.1-7.tl3.3', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'gstreamer1-plugins-good-debuginfo-1.16.1-7.tl3.3', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'gstreamer1-plugins-good-debugsource-1.16.1-7.tl3.3', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'gstreamer1-plugins-good-debugsource-1.16.1-7.tl3.3', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'gstreamer1-plugins-good-gtk-1.16.1-7.tl3.3', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'gstreamer1-plugins-good-gtk-1.16.1-7.tl3.3', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'gstreamer1-plugins-good-gtk-debuginfo-1.16.1-7.tl3.3', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'gstreamer1-plugins-good-gtk-debuginfo-1.16.1-7.tl3.3', '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, 'gstreamer1-plugins-good / gstreamer1-plugins-good-debuginfo / gstreamer1-plugins-good-debugsource / etc');
}