CVE-2020-3119: Cisco NX-OS Software Cisco Discovery Protocol Remote Code Execution Vulnerability

Severity: high (CVSS 8.8 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 4.8% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2020-02-05 · updated 2026-06-17
Weakness: CWE-787

Description

A vulnerability in the Cisco Discovery Protocol implementation for Cisco NX-OS Software could allow an unauthenticated, adjacent attacker to execute arbitrary code or cause a reload on an affected device. The vulnerability exists because the Cisco Discovery Protocol parser does not properly validate input for certain fields in a Cisco Discovery Protocol message. An attacker could exploit this vulnerability by sending a malicious Cisco Discovery Protocol packet to an affected device. An successful exploit could allow the attacker to cause a stack overflow, which could allow the attacker to execute arbitrary code with administrative privileges on an affected device. 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).

Affected products

Cisco NX-OS: from 7.0\(3\)f2 before 9.3\(2\); from 7.0\(3\)i before 7.0\(3\)i7\(8\); from 7.1 before 7.3\(6\)n1\(1\); before 9.3\(2\); from 14.0 before 14.2\(1j\) — fixed in 14.2\(1j\), 7.0\(3\)i7\(8\), 7.3\(6\)n1\(1\), 9.3\(2\)
Cisco Ucs Manager: before 3.2\(3m\); from 4.0 before 4.0\(4f\) — fixed in 3.2\(3m\), 4.0\(4f\)

How to fix

Upgrade to a fixed version: Cisco NX-OS 14.2\(1j\), 7.0\(3\)i7\(8\), 7.3\(6\)n1\(1\), 9.3\(2\); Cisco Ucs Manager 3.2\(3m\), 4.0\(4f\). Check the vendor advisory for mitigations.

References

Get alerted when CVE-2020-3119 or the next vulnerability affects your stack