CVE-2020-3217: Cisco IOS

High severity, CVSS 8.8. EPSS: 1.1% chance of exploitation in the next 30 days.

A vulnerability in the Topology Discovery Service of Cisco One Platform Kit (onePK) in Cisco IOS Software, Cisco IOS XE Software, Cisco IOS XR Software, and Cisco NX-OS Software could allow an unauthenticated, adjacent attacker to execute arbitrary code or cause a denial of service (DoS) condition on an affected device. The vulnerability is due to insufficient length restrictions when the onePK Topology Discovery Service parses Cisco Discovery Protocol messages. An attacker could exploit this vulnerability by sending a malicious Cisco Discovery Protocol message to an affected device. An exploit could allow the attacker to cause a stack overflow, which could allow the attacker to execute arbitrary code with administrative privileges, or to cause a process crash, which could result in a reload of the device and cause a DoS condition.

Affected products

• Cisco IOS: version 12.2(6)i1 only; version 12.4(25e)jao7 only; version 15.0(2)sg11a only; version 15.1(3)svr1 only; version 15.2(1)sy only; version 15.2(1)sy0a only; …
• Cisco IOS XE: version 3.7.0e only; version 3.7.1e only; version 3.7.2e only; version 3.7.3e only; version 3.7.4e only; version 3.7.5e only; …
• Cisco IOS XR: any version
• Cisco NX-OS: version 6.0(2)a only; version 6.0(2)a4(1) only; version 6.0(2)a4(2) only; version 6.0(2)a4(3) only; version 6.0(2)a4(4) only; version 6.0(2)a4(5) only; …

Published 2020-06-03. Last modified 2026-06-17.