Cisco ASA Improper Input Validation (CVE-2019-1687)

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

include('compat.inc');

if (description)
{
  script_id(506075);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/10/06");

  script_cve_id("CVE-2019-1687");

  script_name(english:"Cisco ASA Improper Input Validation (CVE-2019-1687)");

  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 TCP proxy functionality for Cisco Adaptive
Security Appliance (ASA) Software and Cisco Firepower Threat Defense
(FTD) Software could allow an unauthenticated, remote attacker to
cause the device to restart unexpectedly, resulting in a denial of
service (DoS) condition. The vulnerability is due to an error in TCP-
based packet inspection, which could cause the TCP packet to have an
invalid Layer 2 (L2)-formatted header. An attacker could exploit this
vulnerability by sending a crafted TCP packet sequence to the targeted
device. A successful exploit could allow the attacker to cause a DoS
condition.

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-20190501-asa-ftdtcp-dos
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?cb918f3f");
  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-2019-1687");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");
  script_cwe_id(20);

  script_set_attribute(attribute:"vuln_publication_date", value:"2019/05/03");
  script_set_attribute(attribute:"patch_publication_date", value:"2019/05/03");
  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");
  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:9.5" :
        {"versionEndExcluding" : "9.6.4.25", "versionStartIncluding" : "9.5", "family" : "CiscoFirepower"},
    "cpe:/o:cisco:adaptive_security_appliance_software:9.7" :
        {"versionEndExcluding" : "9.8.4", "versionStartIncluding" : "9.7", "family" : "CiscoFirepower"},
    "cpe:/o:cisco:adaptive_security_appliance_software:9.9" :
        {"versionEndExcluding" : "9.9.2.50", "versionStartIncluding" : "9.9", "family" : "CiscoFirepower"},
    "cpe:/o:cisco:adaptive_security_appliance_software:9.10" :
        {"versionEndExcluding" : "9.10.1.17", "versionStartIncluding" : "9.10", "family" : "CiscoFirepower"}
};

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