Cisco ASA Uncontrolled Resource Consumption (CVE-2020-3529)

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

include('compat.inc');

if (description)
{
  script_id(506138);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/10/07");

  script_cve_id("CVE-2020-3529");

  script_name(english:"Cisco ASA Uncontrolled Resource Consumption (CVE-2020-3529)");

  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 SSL VPN negotiation process for Cisco Adaptive
Security Appliance (ASA) Software and Cisco Firepower Threat Defense
(FTD) Software could allow an unauthenticated, remote attacker to
cause a reload of an affected device, resulting in a denial of service
(DoS) condition. The vulnerability is due to inefficient direct memory
access (DMA) memory management during the negotiation phase of an SSL
VPN connection. An attacker could exploit this vulnerability by
sending a steady stream of crafted Datagram TLS (DTLS) traffic to an
affected device. A successful exploit could allow the attacker to
exhaust DMA memory on the device and 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-asaftd-sslvpndma-dos-HRrqB9Yx
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?24a25658");
  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_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-2020-3529");

  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");
  script_cwe_id(400);

  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:"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:9.8.0" :
        {"versionEndExcluding" : "9.8.4.29", "versionStartIncluding" : "9.8.0", "family" : "CiscoFirepower"},
    "cpe:/o:cisco:adaptive_security_appliance_software:9.9.0" :
        {"versionEndExcluding" : "9.9.2.80", "versionStartIncluding" : "9.9.0", "family" : "CiscoFirepower"},
    "cpe:/o:cisco:adaptive_security_appliance_software:9.10.0" :
        {"versionEndExcluding" : "9.10.1.44", "versionStartIncluding" : "9.10.0", "family" : "CiscoFirepower"},
    "cpe:/o:cisco:adaptive_security_appliance_software:9.12.0" :
        {"versionEndExcluding" : "9.12.4.4", "versionStartIncluding" : "9.12.0", "family" : "CiscoFirepower"},
    "cpe:/o:cisco:adaptive_security_appliance_software:9.13.0" :
        {"versionEndExcluding" : "9.13.1.13", "versionStartIncluding" : "9.13.0", "family" : "CiscoFirepower"},
    "cpe:/o:cisco:adaptive_security_appliance_software:9.14.0" :
        {"versionEndExcluding" : "9.14.1.30", "versionStartIncluding" : "9.14.0", "family" : "CiscoFirepower"}
};

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