Cisco ASA Improper Input Validation (CVE-2020-3191)

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

include('compat.inc');

if (description)
{
  script_id(506172);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/10/06");

  script_cve_id("CVE-2020-3191");
  script_xref(name:"CEA-ID", value:"CEA-2020-0042");

  script_name(english:"Cisco ASA Improper Input Validation (CVE-2020-3191)");

  script_set_attribute(attribute:"synopsis", value:
"The remote OT asset is affected by a vulnerability.");
  script_set_attribute(attribute:"description", value:
"A vulnerability in DNS over IPv6 packet processing for Cisco Adaptive
Security Appliance (ASA) Software and Firepower Threat Defense (FTD)
Software could allow an unauthenticated, remote attacker to cause the
device to unexpectedly reload, resulting in a denial of service (DoS)
condition. The vulnerability is due to improper length validation of a
field in an IPv6 DNS packet. An attacker could exploit this
vulnerability by sending a crafted DNS query over IPv6, which
traverses the affected device. An exploit could allow the attacker to
cause the device to reload, resulting in a DoS condition. This
vulnerability is specific to DNS over IPv6 traffic only.

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-ipv6-67pA658k
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?f09a07e9");
  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:P");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2020-3191");
  script_cwe_id(20);

  script_set_attribute(attribute:"vuln_publication_date", value:"2020/05/06");
  script_set_attribute(attribute:"patch_publication_date", value:"2020/05/06");
  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:"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:9.6" :
        {"versionEndExcluding" : "9.6.4.36", "versionStartIncluding" : "9.6", "family" : "CiscoFirepower"},
    "cpe:/o:cisco:adaptive_security_appliance_software:9.8" :
        {"versionEndExcluding" : "9.8.4.12", "versionStartIncluding" : "9.8", "family" : "CiscoFirepower"},
    "cpe:/o:cisco:adaptive_security_appliance_software:9.9" :
        {"versionEndExcluding" : "9.9.2.66", "versionStartIncluding" : "9.9", "family" : "CiscoFirepower"},
    "cpe:/o:cisco:adaptive_security_appliance_software:9.10" :
        {"versionEndExcluding" : "9.10.1.37", "versionStartIncluding" : "9.10", "family" : "CiscoFirepower"},
    "cpe:/o:cisco:adaptive_security_appliance_software:9.12" :
        {"versionEndExcluding" : "9.12.2.9", "versionStartIncluding" : "9.12", "family" : "CiscoFirepower"}
};

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