Erlang/OTP 22.2 < 27.3.4.18 / 28.0 < 28.5.0.7 / 29.0 < 29.1.1 TLS 1.3 Server Authentication Bypass (CVE-2026-89422)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc.
##

include('compat.inc');

if (description)
{
  script_id(350080);
  script_version("1.3");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/09/28");

  script_cve_id("CVE-2026-89422");
  script_xref(name:"IAVA", value:"2026-A-1041");

  script_name(english:"Erlang/OTP 22.2 < 27.3.4.18 / 28.0 < 28.5.0.7 / 29.0 < 29.1.1 TLS 1.3 Server Authentication Bypass (CVE-2026-89422)");

  script_set_attribute(attribute:"synopsis", value:
"The remote host is missing a security update.");
  script_set_attribute(attribute:"description", value:
"The version of Erlang/OTP installed on the remote host is 22.2 prior to 27.3.4.18, 28.0 prior to
28.5.0.7, or 29.0 prior to 29.1.1. It is, therefore, affected by a vulnerability:

  - Key Exchange without Entity Authentication vulnerability in Erlang/OTP ssl allows a peer that
    answers a TLS 1.3 client connection to impersonate the intended server. A pre_shared_key
    extension in the ServerHello that the client never offered causes the client to complete the
    handshake without validating the server's certificate, so ssl:connect returns {ok, Socket}
    against a peer holding no certificate, no private key and no prior session. Certificate path
    validation, verify_fun, hostname verification, partial_chain, CRL checking and OCSP stapling
    are all bypassed. The default client configuration is affected; clients restricted to TLS 1.2
    are not. (CVE-2026-89422)

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://cna.erlef.org/cves/CVE-2026-89422.html");
  script_set_attribute(attribute:"see_also", value:"https://github.com/erlang/otp/security/advisories/GHSA-rgxr-4g4w-j875");
  script_set_attribute(attribute:"solution", value:
"Upgrade to Erlang/OTP version 27.3.4.18, 28.5.0.7, or 29.1.1 or later.");
  script_set_attribute(attribute:"agent", value:"all");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:P/I:P/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:"cvss4_vector", value:"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N");
  script_set_attribute(attribute:"cvss4_threat_vector", value:"CVSS:4.0/E:U");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2026-89422");

  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:"2026/09/22");
  script_set_attribute(attribute:"patch_publication_date", value:"2026/09/22");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/09/25");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:erlang:erlang%2fotp");
  script_set_attribute(attribute:"stig_severity", value:"I");
  script_set_attribute(attribute:"thorough_tests", value:"true");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Misc.");

  script_copyright(english:"This script is Copyright (C) 2026 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("ericcson_erlang_otp_win_installed.nbin", "ericsson_erlang_otp_nix_installed.nbin");
  script_require_keys("installed_sw/Erlang-OTP");

  exit(0);
}

include('vdf.inc');

# @tvdl-content
var vuln_data = {
  'metadata': {'spec_version': '1.0'},
  'checks': [
    {
      'product': {'name': 'Erlang-OTP', 'type': 'app'},
      'check_algorithm': 'default',
      'constraints': [
        {'min_version': '22.2', 'fixed_version': '27.3.4.18'},
        {'min_version': '28.0', 'fixed_version': '28.5.0.7'},
        {'min_version': '29.0', 'fixed_version': '29.1.1'}
      ]
    }
  ]
};

var result = vdf::check_and_report(vuln_data:vuln_data, severity:SECURITY_WARNING);
vdf::handle_check_and_report_errors(vdf_result:result);