Cisco NX-OS Improper Input Validation (CVE-2020-3397)

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

include('compat.inc');

if (description)
{
  script_id(502693);
  script_version("1.5");
  script_set_attribute(attribute:"plugin_modification_date", value:"2025/10/16");

  script_cve_id("CVE-2020-3397");

  script_name(english:"Cisco NX-OS Improper Input Validation (CVE-2020-3397)");

  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 Border Gateway Protocol (BGP) Multicast VPN
(MVPN) implementation of Cisco NX-OS Software could allow an
unauthenticated, remote attacker to cause an affected device to
unexpectedly reload, resulting in a denial of service (DoS) condition.
The vulnerability is due to incomplete input validation of a specific
type of BGP MVPN update message. An attacker could exploit this
vulnerability by sending this specific, valid BGP MVPN update message
to a targeted device. A successful exploit could allow the attacker to
cause one of the BGP-related routing applications to restart multiple
times, leading to a system-level restart. Note: The Cisco
implementation of BGP accepts incoming BGP traffic from only
explicitly configured peers. To exploit this vulnerability, an
attacker must send a specific BGP MVPN update message over an
established TCP connection that appears to come from a trusted BGP
peer. To do so, the attacker must obtain information about the BGP
peers in the trusted network of the affected system.

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-nxosbgp-nlri-dos-458rG2OQ
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?23245ed2");
  # https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-nxosbgp-nlri-dos-458rG2OQ
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?23245ed2");
  script_set_attribute(attribute:"solution", value:
"Refer to the vendor advisory.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/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:C/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-2020-3397");

  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:"2020/08/27");
  script_set_attribute(attribute:"patch_publication_date", value:"2020/08/27");
  script_set_attribute(attribute:"plugin_publication_date", value:"2024/11/29");

  script_set_attribute(attribute:"plugin_type", value:"remote");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:cisco:nexus_3000_series_switches");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:cisco:nexus_9000_series_switches");
  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) 2024-2025 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:nexus_3000_series_switches:7.0%283%29I7%281%29" :
        {"versionEndIncluding" : "7.0%283%29I7%281%29", "versionStartIncluding" : "7.0%283%29I7%281%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_9000_series_switches:7.0%283%29I7%281%29" :
        {"versionEndIncluding" : "7.0%283%29I7%281%29", "versionStartIncluding" : "7.0%283%29I7%281%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_3000_series_switches:7.0%283%29I7%282%29" :
        {"versionEndIncluding" : "7.0%283%29I7%282%29", "versionStartIncluding" : "7.0%283%29I7%282%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_9000_series_switches:7.0%283%29I7%282%29" :
        {"versionEndIncluding" : "7.0%283%29I7%282%29", "versionStartIncluding" : "7.0%283%29I7%282%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_3000_series_switches:7.0%283%29I7%283%29" :
        {"versionEndIncluding" : "7.0%283%29I7%283%29", "versionStartIncluding" : "7.0%283%29I7%283%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_9000_series_switches:7.0%283%29I7%283%29" :
        {"versionEndIncluding" : "7.0%283%29I7%283%29", "versionStartIncluding" : "7.0%283%29I7%283%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_3000_series_switches:7.0%283%29F3%281%29" :
        {"versionEndIncluding" : "7.0%283%29F3%281%29", "versionStartIncluding" : "7.0%283%29F3%281%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_9000_series_switches:7.0%283%29F3%281%29" :
        {"versionEndIncluding" : "7.0%283%29F3%281%29", "versionStartIncluding" : "7.0%283%29F3%281%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_3000_series_switches:7.0%283%29F3%282%29" :
        {"versionEndIncluding" : "7.0%283%29F3%282%29", "versionStartIncluding" : "7.0%283%29F3%282%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_3000_series_switches:7.0%283%29F3%283%29" :
        {"versionEndIncluding" : "7.0%283%29F3%283%29", "versionStartIncluding" : "7.0%283%29F3%283%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_9000_series_switches:7.0%283%29F3%283%29" :
        {"versionEndIncluding" : "7.0%283%29F3%283%29", "versionStartIncluding" : "7.0%283%29F3%283%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_3000_series_switches:7.0%283%29F3%283a%29" :
        {"versionEndIncluding" : "7.0%283%29F3%283a%29", "versionStartIncluding" : "7.0%283%29F3%283a%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_9000_series_switches:7.0%283%29F3%283a%29" :
        {"versionEndIncluding" : "7.0%283%29F3%283a%29", "versionStartIncluding" : "7.0%283%29F3%283a%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_3000_series_switches:7.0%283%29F3%284%29" :
        {"versionEndIncluding" : "7.0%283%29F3%284%29", "versionStartIncluding" : "7.0%283%29F3%284%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_9000_series_switches:7.0%283%29F3%284%29" :
        {"versionEndIncluding" : "7.0%283%29F3%284%29", "versionStartIncluding" : "7.0%283%29F3%284%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_3000_series_switches:7.0%283%29F3%283c%29" :
        {"versionEndIncluding" : "7.0%283%29F3%283c%29", "versionStartIncluding" : "7.0%283%29F3%283c%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_9000_series_switches:7.0%283%29F3%283c%29" :
        {"versionEndIncluding" : "7.0%283%29F3%283c%29", "versionStartIncluding" : "7.0%283%29F3%283c%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_3000_series_switches:7.0%283%29I7%284%29" :
        {"versionEndIncluding" : "7.0%283%29I7%284%29", "versionStartIncluding" : "7.0%283%29I7%284%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_9000_series_switches:7.0%283%29I7%284%29" :
        {"versionEndIncluding" : "7.0%283%29I7%284%29", "versionStartIncluding" : "7.0%283%29I7%284%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_3000_series_switches:9.2%281%29" :
        {"versionEndIncluding" : "9.2%281%29", "versionStartIncluding" : "9.2%281%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_9000_series_switches:9.2%281%29" :
        {"versionEndIncluding" : "9.2%281%29", "versionStartIncluding" : "9.2%281%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_3000_series_switches:7.0%283%29I7%285%29" :
        {"versionEndIncluding" : "7.0%283%29I7%285%29", "versionStartIncluding" : "7.0%283%29I7%285%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_9000_series_switches:7.0%283%29I7%285%29" :
        {"versionEndIncluding" : "7.0%283%29I7%285%29", "versionStartIncluding" : "7.0%283%29I7%285%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_3000_series_switches:7.0%283%29F3%285%29" :
        {"versionEndIncluding" : "7.0%283%29F3%285%29", "versionStartIncluding" : "7.0%283%29F3%285%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_9000_series_switches:7.0%283%29F3%285%29" :
        {"versionEndIncluding" : "7.0%283%29F3%285%29", "versionStartIncluding" : "7.0%283%29F3%285%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_3000_series_switches:7.0%283%29I7%285a%29" :
        {"versionEndIncluding" : "7.0%283%29I7%285a%29", "versionStartIncluding" : "7.0%283%29I7%285a%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_9000_series_switches:7.0%283%29I7%285a%29" :
        {"versionEndIncluding" : "7.0%283%29I7%285a%29", "versionStartIncluding" : "7.0%283%29I7%285a%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_3000_series_switches:7.0%283%29I7%283z%29" :
        {"versionEndIncluding" : "7.0%283%29I7%283z%29", "versionStartIncluding" : "7.0%283%29I7%283z%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_9000_series_switches:7.0%283%29I7%283z%29" :
        {"versionEndIncluding" : "7.0%283%29I7%283z%29", "versionStartIncluding" : "7.0%283%29I7%283z%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_3000_series_switches:7.0%283%29I7%286%29" :
        {"versionEndIncluding" : "7.0%283%29I7%286%29", "versionStartIncluding" : "7.0%283%29I7%286%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_9000_series_switches:7.0%283%29I7%286%29" :
        {"versionEndIncluding" : "7.0%283%29I7%286%29", "versionStartIncluding" : "7.0%283%29I7%286%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_3000_series_switches:7.0%283%29I7%286z%29" :
        {"versionEndIncluding" : "7.0%283%29I7%286z%29", "versionStartIncluding" : "7.0%283%29I7%286z%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_9000_series_switches:7.0%283%29IA7%281%29" :
        {"versionEndIncluding" : "7.0%283%29IA7%281%29", "versionStartIncluding" : "7.0%283%29IA7%281%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_9000_series_switches:7.0%283%29IA7%282%29" :
        {"versionEndIncluding" : "7.0%283%29IA7%282%29", "versionStartIncluding" : "7.0%283%29IA7%282%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_3000_series_switches:7.0%283%29IM7%282%29" :
        {"versionEndIncluding" : "7.0%283%29IM7%282%29", "versionStartIncluding" : "7.0%283%29IM7%282%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_3000_series_switches:9.2%282%29" :
        {"versionEndIncluding" : "9.2%282%29", "versionStartIncluding" : "9.2%282%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_9000_series_switches:9.2%282%29" :
        {"versionEndIncluding" : "9.2%282%29", "versionStartIncluding" : "9.2%282%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_3000_series_switches:9.2%282t%29" :
        {"versionEndIncluding" : "9.2%282t%29", "versionStartIncluding" : "9.2%282t%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_3000_series_switches:9.2%283%29" :
        {"versionEndIncluding" : "9.2%283%29", "versionStartIncluding" : "9.2%283%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_9000_series_switches:9.2%283%29" :
        {"versionEndIncluding" : "9.2%283%29", "versionStartIncluding" : "9.2%283%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_3000_series_switches:9.2%283y%29" :
        {"versionEndIncluding" : "9.2%283y%29", "versionStartIncluding" : "9.2%283y%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_9000_series_switches:9.2%283y%29" :
        {"versionEndIncluding" : "9.2%283y%29", "versionStartIncluding" : "9.2%283y%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_3000_series_switches:9.3%281%29" :
        {"versionEndIncluding" : "9.3%281%29", "versionStartIncluding" : "9.3%281%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_9000_series_switches:9.3%281%29" :
        {"versionEndIncluding" : "9.3%281%29", "versionStartIncluding" : "9.3%281%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_3000_series_switches:9.2%284%29" :
        {"versionEndIncluding" : "9.2%284%29", "versionStartIncluding" : "9.2%284%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_9000_series_switches:9.2%284%29" :
        {"versionEndIncluding" : "9.2%284%29", "versionStartIncluding" : "9.2%284%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_3000_series_switches:7.0%283%29I7%287%29" :
        {"versionEndIncluding" : "7.0%283%29I7%287%29", "versionStartIncluding" : "7.0%283%29I7%287%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_9000_series_switches:7.0%283%29I7%287%29" :
        {"versionEndIncluding" : "7.0%283%29I7%287%29", "versionStartIncluding" : "7.0%283%29I7%287%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_3000_series_switches:9.2%282v%29" :
        {"versionEndIncluding" : "9.2%282v%29", "versionStartIncluding" : "9.2%282v%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_3000_series_switches:9.3%282%29" :
        {"versionEndIncluding" : "9.3%282%29", "versionStartIncluding" : "9.3%282%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_9000_series_switches:9.3%282%29" :
        {"versionEndIncluding" : "9.3%282%29", "versionStartIncluding" : "9.3%282%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_9000_series_switches:9.3%281z%29" :
        {"versionEndIncluding" : "9.3%281z%29", "versionStartIncluding" : "9.3%281z%29", "family" : "NXOS"}
};

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