TencentOS Server 3: gstreamer1-plugins-bad-free (TSSA-2026:0819)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Tencent Linux Security Advisory TSSA-2026:0819.
##

include('compat.inc');

if (description)
{
  script_id(333141);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/08/07");

  script_cve_id("CVE-2026-59691", "CVE-2026-59692");
  script_xref(name:"IAVA", value:"2026-A-0778");

  script_name(english:"TencentOS Server 3: gstreamer1-plugins-bad-free (TSSA-2026:0819)");

  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-2026:0819 advisory.

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

    CVE-2026-59691:
    A heap buffer overflow vulnerability was found in GStreamer's rfbsrc plugin. When a client connects to a
    malicious RFB/VNC server that advertises a 16bpp framebuffer and sends Hextile-encoded updates, the
    Hextile background fill path writes 32-bit pixel values into a buffer allocated for 16-bit pixels. This
    type mismatch causes an out-of-bounds heap write that can lead to denial of service (process crash) and
    potential memory corruption.

    CVE-2026-59692:
    A stack buffer overflow vulnerability was found in GStreamer's DTLS plugin. During a DTLS handshake, the
    peer certificate Subject Distinguished Name is printed into a fixed-size 2048-byte stack buffer without
    bounds checking. A remote unauthenticated attacker can send a certificate with an oversized Subject DN
    that exceeds the buffer, causing a stack buffer overflow and process crash, resulting in denial of
    service.

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-20260819.xml");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/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:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/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-2026-59691");

  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:"2026/07/09");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/07/30");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/08/06");

  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-bad-free");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  script_set_attribute(attribute:"stig_severity", value:"I");
  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-bad-free-1.16.1-9.tl3.1', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'gstreamer1-plugins-bad-free-1.16.1-9.tl3.1', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'gstreamer1-plugins-bad-free-debuginfo-1.16.1-9.tl3.1', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'gstreamer1-plugins-bad-free-debuginfo-1.16.1-9.tl3.1', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'gstreamer1-plugins-bad-free-debugsource-1.16.1-9.tl3.1', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'gstreamer1-plugins-bad-free-debugsource-1.16.1-9.tl3.1', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'gstreamer1-plugins-bad-free-devel-1.16.1-9.tl3.1', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'gstreamer1-plugins-bad-free-devel-1.16.1-9.tl3.1', '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-bad-free / gstreamer1-plugins-bad-free-debuginfo / gstreamer1-plugins-bad-free-debugsource / etc');
}