Cisco NX-OS Improper Input Validation (CVE-2020-3398)

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

include('compat.inc');

if (description)
{
  script_id(502691);
  script_version("1.5");
  script_set_attribute(attribute:"plugin_modification_date", value:"2025/10/16");

  script_cve_id("CVE-2020-3398");

  script_name(english:"Cisco NX-OS Improper Input Validation (CVE-2020-3398)");

  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 a BGP session to repeatedly
reset, causing a partial denial of service (DoS) condition due to the
BGP session being down. The vulnerability is due to incorrect parsing
of a specific type of BGP MVPN update message. An attacker could
exploit this vulnerability by sending this BGP MVPN update message to
a targeted device. A successful exploit could allow the attacker to
cause the BGP peer connections to reset, which could lead to BGP route
instability and impact traffic. The incoming BGP MVPN update message
is valid but is parsed incorrectly by the NX-OS device, which could
send a corrupted BGP update to the configured BGP peer. 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-mvpn-dos-K8kbCrJp
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?07d34ac4");
  # https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-nxosbgp-mvpn-dos-K8kbCrJp
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?07d34ac4");
  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: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: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-2020-3398");

  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_7000_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_7000_series_switches:8.3%281%29" :
        {"versionEndIncluding" : "8.3%281%29", "versionStartIncluding" : "8.3%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_7000_series_switches:8.3%282%29" :
        {"versionEndIncluding" : "8.3%282%29", "versionStartIncluding" : "8.3%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_7000_series_switches:8.4%281%29" :
        {"versionEndIncluding" : "8.4%281%29", "versionStartIncluding" : "8.4%281%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_WARNING);