TencentOS Server 3: go-toolset:rhel8 (TSSA-2026:0648)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Tencent Linux Security Advisory TSSA-2026:0648.
##

include('compat.inc');

if (description)
{
  script_id(328393);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/07/20");

  script_cve_id("CVE-2026-27145", "CVE-2026-39821", "CVE-2026-39822");
  script_xref(name:"IAVB", value:"2026-B-0146");
  script_xref(name:"IAVB", value:"2026-B-0193");

  script_name(english:"TencentOS Server 3: go-toolset:rhel8 (TSSA-2026:0648)");

  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-2026:0648 advisory.

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

    CVE-2026-27145:
    (*x509.Certificate).VerifyHostname previously called matchHostnames in a loop over all DNS Subject
    Alternative Name (SAN) entries. This caused strings.Split(host, .) to execute repeatedly on the same
    input hostname. With a large DNS SAN list, verification costs scaled quadratically based on the number of
    SAN entries multiplied by the hostname's label count. Because x509.Verify validates hostnames before
    building the certificate chain, this overhead occurred even for untrusted certificates.

    CVE-2026-39821:
    The ToASCII and ToUnicode functions incorrectly accept Punycode-encoded labels that decode to an ASCII-
    only label. For example, ToUnicode(xn--example-.com) incorrectly returns the name example.com rather
    than an error. This behavior can lead to privilege escalation in programs using the idna package. For
    example, a program which performs privilege checks on the ASCII hostname may reject example.com but
    permit xn--example-.com. If that program subsequently converts the ASCII hostname to Unicode, it will
    inadvertently permits access to the Unicode name example.com.

    CVE-2026-39822:
    On Unix systems, opening a file in an os.Root improperly follows symlinks to locations outside of the Root
    when the final path component of the a path is a symbolic link and the path ends in /. For example,
    'root.Open(symlink/)' will open symlink even when symlink is a symbolic link pointing outside of the
    root.

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-20260648.xml");
  script_set_attribute(attribute:"solution", value:
"Update the affected packages.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:N");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-39821");

  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:"2026/05/12");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/07/13");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/07/20");

  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:delve");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:tencent:tencentos_server:golang");
  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':'delve-1.26.1-1.module+el8.10.0+935+e1334de7', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'delve-1.26.1-1.module+el8.10.0+935+e1334de7', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'delve-debuginfo-1.26.1-1.module+el8.10.0+935+e1334de7', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'delve-debuginfo-1.26.1-1.module+el8.10.0+935+e1334de7', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'delve-debugsource-1.26.1-1.module+el8.10.0+935+e1334de7', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'delve-debugsource-1.26.1-1.module+el8.10.0+935+e1334de7', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'go-toolset-1.26.5-1.module+el8.10.0+935+e1334de7.ap.1', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'go-toolset-1.26.5-1.module+el8.10.0+935+e1334de7.ap.1', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'golang-1.26.5-1.module+el8.10.0+935+e1334de7.ap.1', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'golang-1.26.5-1.module+el8.10.0+935+e1334de7.ap.1', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'golang-bin-1.26.5-1.module+el8.10.0+935+e1334de7.ap.1', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'golang-bin-1.26.5-1.module+el8.10.0+935+e1334de7.ap.1', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'golang-docs-1.26.5-1.module+el8.10.0+935+e1334de7.ap.1', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'golang-misc-1.26.5-1.module+el8.10.0+935+e1334de7.ap.1', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'golang-race-1.26.5-1.module+el8.10.0+935+e1334de7.ap.1', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'golang-race-1.26.5-1.module+el8.10.0+935+e1334de7.ap.1', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'golang-src-1.26.5-1.module+el8.10.0+935+e1334de7.ap.1', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'golang-tests-1.26.5-1.module+el8.10.0+935+e1334de7.ap.1', '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, 'delve / delve-debuginfo / delve-debugsource / etc');
}