TencentOS Server 4: openssl (TSSA-2026:0503)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
#
# The descriptive text and package checks in this plugin were
# extracted from Tencent Linux Security Advisory TSSA-2026:0503.
##

include('compat.inc');

if (description)
{
  script_id(325856);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/07/09");

  script_cve_id("CVE-2026-34182", "CVE-2026-45447");
  script_xref(name:"IAVA", value:"2026-A-0589");

  script_name(english:"TencentOS Server 4: openssl (TSSA-2026:0503)");

  script_set_attribute(attribute:"synopsis", value:
"The remote TencentOS Server 4 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 4 host is prior to tested version. It is,
therefore, affected by multiple vulnerabilities as referenced in the TSSA-2026:0503 advisory.

    Package updates are available for TencentOS Server 4 that fix the following vulnerabilities:

    CVE-2026-45447:
    Issue summary: A specially crafted PKCS#7 or S/MIME signed message could
    trigger a use-after-free during PKCS#7 signature verification.

    Impact summary: A use-after-free may result in process crashes, heap
    corruption, or potentially remote code execution.

    When processing a PKCS#7 or S/MIME signed message, if the SignedData
    digestAlgorithms field is present as an empty ASN.1 SET, OpenSSL may
    incorrectly free a caller-owned BIO during PKCS7_verify(). A subsequent
    use of the BIO by the calling application results in a use-after-free
    condition.

    In the common case this occurs when the application later calls
    BIO_free() on the BIO originally passed to PKCS7_verify(). Depending
    on allocator behavior and application-specific BIO usage patterns, this
    may result in a crash or other memory corruption. In some application
    contexts this may potentially be exploitable for remote code execution.

    Applications that process PKCS#7 or S/MIME signed messages using OpenSSL
    PKCS#7 APIs may be affected. Applications using the CMS APIs for this
    processing are not affected.

    The FIPS modules in 4.0, 3.6, 3.5, 3.4, and 3.0 are not affected by this
    issue, as the affected code is outside the OpenSSL FIPS module boundary.

    CVE-2026-34182:
    Issue Summary: Cryptographic Message Services (CMS) processing fails to perform
    sufficient input validation on the cipher and tag length fields of
    AuthEnvelopedData containers, leading to various potential compromises.

    Impact Summary: Attackers making use of these vulnerabilities may achieve
    key-equivalent functionality for a given CMS recipient and/or bypass integrity
    validation for a given message.

    In one use case, an attacker may send a CMS message containing
    AuthEnvelopedData with the cipher specified as a non-AEAD cipher.  OpenSSL
    erroneously allows this selection, and attempts to decrypt and validate the
    message.

    An on-path attacker who captures one legitimate AES-GCM AuthEnvelopedData
    addressed to the victim can re-emit it with the recipientInfos set left
    byte-for-byte intact, so the victim's private key still unwraps the genuine CEK
    (the content-encryption key), but with the inner OID rewritten to AES-256-OFB
    (Output Feedback Mode, an unauthenticated keystream mode) and with an
    attacker-chosen IV and ciphertext. The victim initializes AES-256-OFB under the
    real CEK, never consults the MAC field, and CMS_decrypt() returns success.

    If the application under attack responds to the attacker with any indicator
    showing success or failure of the decryption effort, it is possible for the
    attacker to use this as an oracle to obtain key equivalent functionality for the
    CEK used for the chosen recipient of the message.

    In another use case, an attacker can reduce the tag length of the chosen AEAD
    cipher for a given AuthEnvelopedData container to be a single byte long,
    allowing an attacker to brute force CMS decryption, producing an integrity
    bypass for applications that trust CMS_decrypt() to reject modified content.

    The FIPS modules are not affected by this issue.

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-20260503.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: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: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-2026-45447");
  script_set_attribute(attribute:"cvss3_score_source", value:"CVE-2026-34182");

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

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:tencent:tencentos_server:4");
  script_set_attribute(attribute:"cpe", value:"p-cpe:/a:tencent:tencentos_server:openssl");
  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:"^4([^0-9]|$)", string:os_version)) audit(AUDIT_OS_NOT, 'TencentOS 4.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': '4',
    'pkgs': [
      {'reference':'openssl-3.0.12-27.tl4', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'openssl-3.0.12-27.tl4', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'openssl-debuginfo-3.0.12-27.tl4', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'openssl-debuginfo-3.0.12-27.tl4', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'openssl-debugsource-3.0.12-27.tl4', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'openssl-debugsource-3.0.12-27.tl4', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'openssl-devel-3.0.12-27.tl4', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'openssl-devel-3.0.12-27.tl4', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'openssl-libs-3.0.12-27.tl4', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'openssl-libs-3.0.12-27.tl4', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'openssl-libs-debuginfo-3.0.12-27.tl4', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'openssl-libs-debuginfo-3.0.12-27.tl4', 'cpu':'x86_64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'openssl-perl-3.0.12-27.tl4', 'cpu':'aarch64', 'rpm_spec_vers_cmp':TRUE},
      {'reference':'openssl-perl-3.0.12-27.tl4', '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, 'openssl / openssl-debuginfo / openssl-debugsource / etc');
}