TencentOS Server 3: mod_auth_openidc:2.3 (TSSA-2026:1397)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Tencent Linux Security Advisory TSSA-2026:1397.
##

include('compat.inc');

if (description)
{
  script_id(379316);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/11/11");

  script_cve_id("CVE-2026-53939");

  script_name(english:"TencentOS Server 3: mod_auth_openidc:2.3 (TSSA-2026:1397)");

  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 a vulnerability as referenced in the TSSA-2026:1397 advisory.

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

    CVE-2026-53939:
    OpenIDC/cjose is a C library implementing the Javascript Object Signing and Encryption (JOSE). In versions
    0.6.1 through 0.6.2.5, when cjose encrypts a JWE using an AES-CBC-HMAC content-encryption algorithm
    (A128CBC-HS256, A192CBC-HS384, or A256CBC-HS512) together with any key-management algorithm that generates
    a fresh content-encryption key (CEK), the CEK is all zero bytes instead of being randomly generated. The
    resulting JWE is therefore encrypted and authenticated under a fixed, publicly known key, so anyone who
    obtains the JWE can recover the plaintext and forge or modify the content. This is fixed in version
    0.6.2.6 by _cjose_jwe_set_cek_aes_cbc() generating the CEK from RAND_bytes. A regression test asserts that
    the encrypted_key differs across two encryptions for each AES-CBC-HMAC variant. Until upgrading, for data
    encrypted with cjose, three options are available. Use an AES-GCM enc (A128GCM / A192GCM / A256GCM)
    instead of an AES-CBC-HMAC enc,  use alg=dir with a caller-supplied CEK, or avoid using cjose for JWE
    encryption with the affected algorithm pair. These are mitigations for new ciphertexts only; data already
    encrypted under the zero key remains compromised and should be re-encrypted (and any secrets it contained
    rotated).

Tenable has extracted the preceding description block directly from the Tencent Linux security advisory.

Note that Nessus has not tested for this issue 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-20261397.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:L/PR:N/UI:N/S:U/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-2026-53939");

  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:"2026/09/08");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/10/29");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/11/11");

  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:cjose");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:tencent:tencentos_server:mod_auth_openidc");
  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':'cjose-0.6.1-6.module+el8.10.0+990+92d36675', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'cjose-0.6.1-6.module+el8.10.0+990+92d36675', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'cjose-debuginfo-0.6.1-6.module+el8.10.0+990+92d36675', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'cjose-debuginfo-0.6.1-6.module+el8.10.0+990+92d36675', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'cjose-debugsource-0.6.1-6.module+el8.10.0+990+92d36675', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'cjose-debugsource-0.6.1-6.module+el8.10.0+990+92d36675', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'cjose-devel-0.6.1-6.module+el8.10.0+990+92d36675', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'cjose-devel-0.6.1-6.module+el8.10.0+990+92d36675', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'mod_auth_openidc-2.4.9.4-9.module+el8.10.0+990+92d36675', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'mod_auth_openidc-2.4.9.4-9.module+el8.10.0+990+92d36675', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'mod_auth_openidc-debuginfo-2.4.9.4-9.module+el8.10.0+990+92d36675', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'mod_auth_openidc-debuginfo-2.4.9.4-9.module+el8.10.0+990+92d36675', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'mod_auth_openidc-debugsource-2.4.9.4-9.module+el8.10.0+990+92d36675', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'mod_auth_openidc-debugsource-2.4.9.4-9.module+el8.10.0+990+92d36675', '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, 'cjose / cjose-debuginfo / cjose-debugsource / etc');
}