Cisco FXOS and NX-OS Software Cisco Discovery Protocol Arbitrary Code Execution and Denial of Service (CVE-2020-3172)

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

include('compat.inc');

if (description)
{
  script_id(501238);
  script_version("1.2");
  script_set_attribute(attribute:"plugin_modification_date", value:"2025/10/16");

  script_cve_id("CVE-2020-3172");

  script_name(english:"Cisco FXOS and NX-OS Software Cisco Discovery Protocol Arbitrary Code Execution and Denial of Service (CVE-2020-3172)");

  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 Cisco Discovery Protocol feature of Cisco FXOS
Software and Cisco NX-OS Software could allow an unauthenticated,
adjacent attacker to execute arbitrary code as root or cause a denial
of service (DoS) condition on an affected device. The vulnerability
exists because of insufficiently validated Cisco Discovery Protocol
packet headers. An attacker could exploit this vulnerability by
sending a crafted Cisco Discovery Protocol packet to a Layer
2-adjacent affected device. A successful exploit could allow the
attacker to cause a buffer overflow that could allow the attacker to
execute arbitrary code as root or cause a DoS condition on the
affected device. Note: Cisco Discovery Protocol is a Layer 2 protocol.
To exploit this vulnerability, an attacker must be in the same
broadcast domain as the affected device (Layer 2 adjacent). Note: This
vulnerability is different from the following Cisco FXOS and NX-OS
Software Cisco Discovery Protocol vulnerabilities that Cisco announced
on Feb. 5, 2020: Cisco FXOS, IOS XR, and NX-OS Software Cisco
Discovery Protocol Denial of Service Vulnerability and Cisco NX-OS
Software Cisco Discovery Protocol Remote Code Execution Vulnerability.

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-20200226-fxos-nxos-cdp
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?be9c7431");
  script_set_attribute(attribute:"solution", value:
"Refer to the vendor advisory.");
  script_set_cvss_base_vector("CVSS2#AV:A/AC:L/Au:N/C:C/I:C/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/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-2020-3172");

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

  script_set_attribute(attribute:"vuln_publication_date", value:"2020/02/26");
  script_set_attribute(attribute:"patch_publication_date", value:"2020/02/26");
  script_set_attribute(attribute:"plugin_publication_date", value:"2023/07/25");

  script_set_attribute(attribute:"plugin_type", value:"remote");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:cisco:nexus_1000v_series_switches");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:cisco:nexus_3000_series_switches");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:cisco:nexus_5000_series_switches");
  script_set_attribute(attribute:"cpe", value:"cpe:/o:cisco:nexus_6000_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) 2023-2025 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_5000_series_switches:7.3%280%29N1%281%29" :
        {"versionEndIncluding" : "7.3%280%29N1%281%29", "versionStartIncluding" : "7.3%280%29N1%281%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_6000_series_switches:7.3%280%29N1%281%29" :
        {"versionEndIncluding" : "7.3%280%29N1%281%29", "versionStartIncluding" : "7.3%280%29N1%281%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_5000_series_switches:7.3%281%29N1%281%29" :
        {"versionEndIncluding" : "7.3%281%29N1%281%29", "versionStartIncluding" : "7.3%281%29N1%281%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_6000_series_switches:7.3%281%29N1%281%29" :
        {"versionEndIncluding" : "7.3%281%29N1%281%29", "versionStartIncluding" : "7.3%281%29N1%281%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_5000_series_switches:7.3%282%29N1%281%29" :
        {"versionEndIncluding" : "7.3%282%29N1%281%29", "versionStartIncluding" : "7.3%282%29N1%281%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_6000_series_switches:7.3%282%29N1%281%29" :
        {"versionEndIncluding" : "7.3%282%29N1%281%29", "versionStartIncluding" : "7.3%282%29N1%281%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_5000_series_switches:7.3%280%29N1%281b%29" :
        {"versionEndIncluding" : "7.3%280%29N1%281b%29", "versionStartIncluding" : "7.3%280%29N1%281b%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_6000_series_switches:7.3%280%29N1%281b%29" :
        {"versionEndIncluding" : "7.3%280%29N1%281b%29", "versionStartIncluding" : "7.3%280%29N1%281b%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_5000_series_switches:7.3%280%29N1%281a%29" :
        {"versionEndIncluding" : "7.3%280%29N1%281a%29", "versionStartIncluding" : "7.3%280%29N1%281a%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_6000_series_switches:7.3%280%29N1%281a%29" :
        {"versionEndIncluding" : "7.3%280%29N1%281a%29", "versionStartIncluding" : "7.3%280%29N1%281a%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_3000_series_switches:6.0%282%29A8%281%29" :
        {"versionEndIncluding" : "6.0%282%29A8%281%29", "versionStartIncluding" : "6.0%282%29A8%281%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_3000_series_switches:6.0%282%29A8%282%29" :
        {"versionEndIncluding" : "6.0%282%29A8%282%29", "versionStartIncluding" : "6.0%282%29A8%282%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_3000_series_switches:6.0%282%29A8%283%29" :
        {"versionEndIncluding" : "6.0%282%29A8%283%29", "versionStartIncluding" : "6.0%282%29A8%283%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_3000_series_switches:6.0%282%29A8%284%29" :
        {"versionEndIncluding" : "6.0%282%29A8%284%29", "versionStartIncluding" : "6.0%282%29A8%284%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_3000_series_switches:6.0%282%29A8%284a%29" :
        {"versionEndIncluding" : "6.0%282%29A8%284a%29", "versionStartIncluding" : "6.0%282%29A8%284a%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_3000_series_switches:6.0%282%29A8%285%29" :
        {"versionEndIncluding" : "6.0%282%29A8%285%29", "versionStartIncluding" : "6.0%282%29A8%285%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_3000_series_switches:6.0%282%29A8%286%29" :
        {"versionEndIncluding" : "6.0%282%29A8%286%29", "versionStartIncluding" : "6.0%282%29A8%286%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_3000_series_switches:6.0%282%29A8%287%29" :
        {"versionEndIncluding" : "6.0%282%29A8%287%29", "versionStartIncluding" : "6.0%282%29A8%287%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_3000_series_switches:6.0%282%29A8%287a%29" :
        {"versionEndIncluding" : "6.0%282%29A8%287a%29", "versionStartIncluding" : "6.0%282%29A8%287a%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_3000_series_switches:6.0%282%29A8%287b%29" :
        {"versionEndIncluding" : "6.0%282%29A8%287b%29", "versionStartIncluding" : "6.0%282%29A8%287b%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_3000_series_switches:6.0%282%29A8%288%29" :
        {"versionEndIncluding" : "6.0%282%29A8%288%29", "versionStartIncluding" : "6.0%282%29A8%288%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_3000_series_switches:6.0%282%29A8%289%29" :
        {"versionEndIncluding" : "6.0%282%29A8%289%29", "versionStartIncluding" : "6.0%282%29A8%289%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_5000_series_switches:7.3%283%29N1%281%29" :
        {"versionEndIncluding" : "7.3%283%29N1%281%29", "versionStartIncluding" : "7.3%283%29N1%281%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_6000_series_switches:7.3%283%29N1%281%29" :
        {"versionEndIncluding" : "7.3%283%29N1%281%29", "versionStartIncluding" : "7.3%283%29N1%281%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_3000_series_switches:6.0%282%29A8%2810a%29" :
        {"versionEndIncluding" : "6.0%282%29A8%2810a%29", "versionStartIncluding" : "6.0%282%29A8%2810a%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_3000_series_switches:6.0%282%29A8%2810%29" :
        {"versionEndIncluding" : "6.0%282%29A8%2810%29", "versionStartIncluding" : "6.0%282%29A8%2810%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_5000_series_switches:7.3%284%29N1%281%29" :
        {"versionEndIncluding" : "7.3%284%29N1%281%29", "versionStartIncluding" : "7.3%284%29N1%281%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_6000_series_switches:7.3%284%29N1%281%29" :
        {"versionEndIncluding" : "7.3%284%29N1%281%29", "versionStartIncluding" : "7.3%284%29N1%281%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_3000_series_switches:6.0%282%29A8%2811%29" :
        {"versionEndIncluding" : "6.0%282%29A8%2811%29", "versionStartIncluding" : "6.0%282%29A8%2811%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_3000_series_switches:6.0%282%29A8%2811a%29" :
        {"versionEndIncluding" : "6.0%282%29A8%2811a%29", "versionStartIncluding" : "6.0%282%29A8%2811a%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_5000_series_switches:7.3%282%29N1%281b%29" :
        {"versionEndIncluding" : "7.3%282%29N1%281b%29", "versionStartIncluding" : "7.3%282%29N1%281b%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_6000_series_switches:7.3%282%29N1%281b%29" :
        {"versionEndIncluding" : "7.3%282%29N1%281b%29", "versionStartIncluding" : "7.3%282%29N1%281b%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_5000_series_switches:7.3%282%29N1%281c%29" :
        {"versionEndIncluding" : "7.3%282%29N1%281c%29", "versionStartIncluding" : "7.3%282%29N1%281c%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_6000_series_switches:7.3%282%29N1%281c%29" :
        {"versionEndIncluding" : "7.3%282%29N1%281c%29", "versionStartIncluding" : "7.3%282%29N1%281c%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_5000_series_switches:7.3%284%29N1%281a%29" :
        {"versionEndIncluding" : "7.3%284%29N1%281a%29", "versionStartIncluding" : "7.3%284%29N1%281a%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_6000_series_switches:7.3%284%29N1%281a%29" :
        {"versionEndIncluding" : "7.3%284%29N1%281a%29", "versionStartIncluding" : "7.3%284%29N1%281a%29", "family" : "NXOS"},
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        {"versionEndIncluding" : "7.3%285%29N1%281%29", "versionStartIncluding" : "7.3%285%29N1%281%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_6000_series_switches:7.3%285%29N1%281%29" :
        {"versionEndIncluding" : "7.3%285%29N1%281%29", "versionStartIncluding" : "7.3%285%29N1%281%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_1000v_series_switches:5.2%281%29SV5%281.1%29" :
        {"versionEndIncluding" : "5.2%281%29SV5%281.1%29", "versionStartIncluding" : "5.2%281%29SV5%281.1%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_1000v_series_switches:5.2%281%29SV5%281.2%29" :
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    "cpe:/o:cisco:nexus_5000_series_switches:7.3%286%29N1%281%29" :
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    "cpe:/o:cisco:nexus_6000_series_switches:7.3%286%29N1%281%29" :
        {"versionEndIncluding" : "7.3%286%29N1%281%29", "versionStartIncluding" : "7.3%286%29N1%281%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_5000_series_switches:7.3%286%29N1%281a%29" :
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        {"versionEndIncluding" : "13.2%281m%29", "versionStartIncluding" : "13.2%281m%29", "family" : "NXOS"},
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    "cpe:/o:cisco:nexus_9000_series_switches:13.2%283r%29" :
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    "cpe:/o:cisco:nexus_9000_series_switches:13.2%284e%29" :
        {"versionEndIncluding" : "13.2%284e%29", "versionStartIncluding" : "13.2%284e%29", "family" : "NXOS"},
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        {"versionEndIncluding" : "14.0%283d%29", "versionStartIncluding" : "14.0%283d%29", "family" : "NXOS"},
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    "cpe:/o:cisco:nexus_9000_series_switches:13.2%287f%29" :
        {"versionEndIncluding" : "13.2%287f%29", "versionStartIncluding" : "13.2%287f%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_9000_series_switches:13.2%287k%29" :
        {"versionEndIncluding" : "13.2%287k%29", "versionStartIncluding" : "13.2%287k%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_9000_series_switches:14.1%282m%29" :
        {"versionEndIncluding" : "14.1%282m%29", "versionStartIncluding" : "14.1%282m%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_9000_series_switches:14.1%282o%29" :
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    "cpe:/o:cisco:nexus_9000_series_switches:14.1%282u%29" :
        {"versionEndIncluding" : "14.1%282u%29", "versionStartIncluding" : "14.1%282u%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_9000_series_switches:14.2%281i%29" :
        {"versionEndIncluding" : "14.2%281i%29", "versionStartIncluding" : "14.2%281i%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_9000_series_switches:14.1%282w%29" :
        {"versionEndIncluding" : "14.1%282w%29", "versionStartIncluding" : "14.1%282w%29", "family" : "NXOS"},
    "cpe:/o:cisco:nexus_9000_series_switches:14.1%282x%29" :
        {"versionEndIncluding" : "14.1%282x%29", "versionStartIncluding" : "14.1%282x%29", "family" : "NXOS"}
};

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