Cisco ASA Incorrect Conversion Between Numeric Types (CVE-2023-20006)

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

include('compat.inc');

if (description)
{
  script_id(506056);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/10/06");

  script_cve_id("CVE-2023-20006");

  script_name(english:"Cisco ASA Incorrect Conversion Between Numeric Types (CVE-2023-20006)");

  script_set_attribute(attribute:"synopsis", value:
"The remote OT asset is affected by a vulnerability.");
  script_set_attribute(attribute:"description", value:
"A vulnerability in the hardware-based SSL/TLS cryptography
functionality of Cisco Adaptive Security Appliance (ASA) Software and
Cisco Firepower Threat Defense (FTD) Software for Cisco Firepower 2100
Series Appliances could allow an unauthenticated, remote attacker to
cause an affected device to reload unexpectedly, resulting in a denial
of service (DoS) condition. This vulnerability is due to an
implementation error within the cryptographic functions for SSL/TLS
traffic processing when they are offloaded to the hardware. An
attacker could exploit this vulnerability by sending a crafted stream
of SSL/TLS traffic to an affected device. A successful exploit could
allow the attacker to cause an unexpected error in the hardware-based
cryptography engine, which could cause the device to reload.

This plugin only works with Tenable.ot.
Please visit https://www.tenable.com/products/tenable-ot for more information.");
  # https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-ssl-dos-uu7mV5p6
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?4af295e8");
  script_set_attribute(attribute:"solution", value:
"Refer to the vendor advisory.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:N/I:N/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:N/I:N/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-2023-20006");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");
  script_cwe_id(681);

  script_set_attribute(attribute:"vuln_publication_date", value:"2023/06/28");
  script_set_attribute(attribute:"patch_publication_date", value:"2023/06/28");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/10/05");

  script_set_attribute(attribute:"plugin_type", value:"remote");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:cisco:adaptive_security_appliance_software:9.16.4");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:cisco:adaptive_security_appliance_software:9.18.2");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:cisco:adaptive_security_appliance_software:9.18.2.5");
  script_set_attribute(attribute:"generated_plugin", value:"former");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Tenable.ot");

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

  script_dependencies("tenable_ot_api_integration.nasl");
  script_require_keys("Tenable.ot/Cisco");

  exit(0);
}


include('tenable_ot_cve_funcs.inc');

get_kb_item_or_exit('Tenable.ot/Cisco');

var asset = tenable_ot::assets::get(vendor:'Cisco');

var vuln_cpes = {
    "cpe:/o:cisco:adaptive_security_appliance_software:9.16.4" :
        {"versionEndIncluding" : "9.16.4", "versionStartIncluding" : "9.16.4", "family" : "CiscoFirepower"},
    "cpe:/o:cisco:adaptive_security_appliance_software:9.18.2" :
        {"versionEndIncluding" : "9.18.2", "versionStartIncluding" : "9.18.2", "family" : "CiscoFirepower"},
    "cpe:/o:cisco:adaptive_security_appliance_software:9.18.2.5" :
        {"versionEndIncluding" : "9.18.2.5", "versionStartIncluding" : "9.18.2.5", "family" : "CiscoFirepower"}
};

tenable_ot::cve::compare_and_report(asset:asset, cpes:vuln_cpes, severity:SECURITY_HOLE);