Cisco (CVE-2022-20795)

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

include('compat.inc');

if (description)
{
  script_id(505940);
  script_version("1.1");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/08/11");

  script_cve_id("CVE-2022-20795");

  script_name(english:"Cisco (CVE-2022-20795)");

  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 implementation of the Datagram TLS (DTLS)
protocol in Cisco Adaptive Security Appliance (ASA) Software and Cisco
Firepower Threat Defense (FTD) Software could allow an
unauthenticated, remote attacker to cause high CPU utilization,
resulting in a denial of service (DoS) condition. This vulnerability
is due to suboptimal processing that occurs when establishing a DTLS
tunnel as part of an AnyConnect SSL VPN connection. An attacker could
exploit this vulnerability by sending a steady stream of crafted DTLS
traffic to an affected device. A successful exploit could allow the
attacker to exhaust resources on the affected VPN headend device. This
could cause existing DTLS tunnels to stop passing traffic and prevent
new DTLS tunnels from establishing, resulting in a DoS condition.
Note: When the attack traffic stops, the device recovers gracefully.

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-vpndtls-dos-TunzLEV
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?864a3e06");
  # https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-vpndtls-dos-TunzLEV
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?864a3e06");
  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:U/C:N/I:N/A:H");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2022-20795");
  script_cwe_id(345, 345);

  script_set_attribute(attribute:"vuln_publication_date", value:"2022/04/21");
  script_set_attribute(attribute:"patch_publication_date", value:"2022/04/21");
  script_set_attribute(attribute:"plugin_publication_date", value:"2026/08/11");

  script_set_attribute(attribute:"plugin_type", value:"remote");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:cisco:adaptive_security_appliance_software");
  script_set_attribute(attribute:"generated_plugin", value:"current");
  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" :
        {"versionEndIncluding" : "9.17.1.9", "versionStartIncluding" : "9.17.0", "family" : "CiscoFirepower"}
};

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