Cisco FXOS, IOS XR, and NX-OS Software Cisco Discovery Protocol Denial of Service (CVE-2020-3120)

medium Tenable OT Security Plugin ID 501267

Synopsis

The remote OT asset is affected by a vulnerability.

Description

A vulnerability in the Cisco Discovery Protocol implementation for Cisco FXOS Software, Cisco IOS XR Software, and Cisco NX-OS Software could allow an unauthenticated, adjacent attacker to cause a reload of an affected device, resulting in a denial of service (DoS) condition.
The vulnerability is due to a missing check when the affected software processes Cisco Discovery Protocol messages. An attacker could exploit this vulnerability by sending a malicious Cisco Discovery Protocol packet to an affected device. A successful exploit could allow the attacker to exhaust system memory, causing the device to reload. 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).

This plugin only works with Tenable.ot.
Please visit https://www.tenable.com/products/tenable-ot for more information.

Solution

Refer to the vendor advisory.

Plugin Details

Severity: Medium

ID: 501267

Version: 1.3

Type: remote

Family: Tenable.ot

Published: 7/25/2023

Updated: 10/16/2025

Supported Sensors: Tenable OT Security

Risk Information

VPR

Risk Factor: Low

Score: 3.6

CVSS v2

Risk Factor: Medium

Base Score: 6.1

Temporal Score: 4.5

Vector: CVSS2#AV:A/AC:L/Au:N/C:N/I:N/A:C

CVSS Score Source: CVE-2020-3120

CVSS v3

Risk Factor: Medium

Base Score: 6.5

Temporal Score: 5.7

Vector: CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

CPE: cpe:/o:cisco:nexus_7000_series_switches, cpe:/o:cisco:nexus_5000_series_switches, cpe:/o:cisco:nexus_3000_series_switches, cpe:/o:cisco:nexus_9000_series_switches, cpe:/o:cisco:nexus_6000_series_switches, cpe:/o:cisco:nexus_1000v_series_switches

Required KB Items: Tenable.ot/Cisco

Exploit Ease: No known exploits are available

Patch Publication Date: 2/5/2020

Vulnerability Publication Date: 2/5/2020

Reference Information

CVE: CVE-2020-3120

CWE: 190

Detections

Analytics