CVE-2020-3235: Cisco IOS

High severity, CVSS 7.7. EPSS: 1.6% chance of exploitation in the next 30 days.

A vulnerability in the Simple Network Management Protocol (SNMP) subsystem of Cisco IOS Software and Cisco IOS XE Software on Catalyst 4500 Series Switches could allow an authenticated, remote attacker to cause a denial of service (DoS) condition. The vulnerability is due to insufficient input validation when the software processes specific SNMP object identifiers. An attacker could exploit this vulnerability by sending a crafted SNMP packet to an affected device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition. Note: To exploit this vulnerability by using SNMPv2c or earlier, the attacker must know the SNMP read-only community string for an affected system. To exploit this vulnerability by using SNMPv3, the attacker must know the user credentials for the affected system.

Affected products

• Cisco IOS: version 12.2(52)sg only; version 12.2(53)sg1 only; version 12.2(53)sg2 only; version 12.2(53)sg3 only; version 12.2(53)sg4 only; version 12.2(53)sg5 only; …
• Cisco IOS XE: version 3.2.0sg only; version 3.2.1sg only; version 3.2.2sg only; version 3.2.3sg only; version 3.2.4sg only; version 3.2.5sg only; …
• Oracle Goldengate Management Pack: version 12.2.1.2.0 only

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