Cisco ASA/FTD Observable Discrepancy (CVE-2020-3585)

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

include('compat.inc');

if (description)
{
  script_id(506133);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/10/07");

  script_cve_id("CVE-2020-3585");

  script_name(english:"Cisco ASA/FTD Observable Discrepancy (CVE-2020-3585)");

  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 TLS handler of Cisco Adaptive Security
Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD)
Software for Cisco Firepower 1000 Series firewalls could allow an
unauthenticated, remote attacker to gain access to sensitive
information. The vulnerability is due to improper implementation of
countermeasures against the Bleichenbacher attack for cipher suites
that rely on RSA for key exchange. An attacker could exploit this
vulnerability by sending crafted TLS messages to the device, which
would act as an oracle and allow the attacker to carry out a chosen-
ciphertext attack. A successful exploit could allow the attacker to
perform cryptanalytic operations that may allow decryption of
previously captured TLS sessions to the affected device. To exploit
this vulnerability, an attacker must be able to perform both of the
following actions: Capture TLS traffic that is in transit between
clients and the affected device Actively establish a considerable
number of TLS connections to the affected device

This plugin only works with Tenable.ot.
Please visit https://www.tenable.com/products/tenable-ot for more information.");
  # https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asaftd-tls-bb-2g9uWkP
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?5c27f3ff");
  script_set_attribute(attribute:"solution", value:
"Refer to the vendor advisory.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:P/I:N/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:N/UI:N/S:U/C:L/I:N/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-2020-3585");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");
  script_cwe_id(203);

  script_set_attribute(attribute:"vuln_publication_date", value:"2020/10/21");
  script_set_attribute(attribute:"patch_publication_date", value:"2020/10/21");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/10/06");

  script_set_attribute(attribute:"plugin_type", value:"remote");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:cisco:adaptive_security_appliance_software:9");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:cisco:firepower_threat_defense:6");
  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:firepower_threat_defense:6.5.0" :
        {"versionEndExcluding" : "6.5.0.5", "versionStartIncluding" : "6.5.0", "family" : "CiscoFirepower"},
    "cpe:/o:cisco:firepower_threat_defense:6.6.0" :
        {"versionEndExcluding" : "6.6.1", "versionStartIncluding" : "6.6.0", "family" : "CiscoFirepower"},
    "cpe:/o:cisco:adaptive_security_appliance_software:9" :
        {"versionEndExcluding" : "9.13.1.13", "family" : "CiscoFirepower"},
    "cpe:/o:cisco:adaptive_security_appliance_software:9.14" :
        {"versionEndExcluding" : "9.14.1.30", "versionStartIncluding" : "9.14", "family" : "CiscoFirepower"}
};

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