CVE-2025-20172: Cisco IOS

High severity, CVSS 7.7. EPSS: 0.8% chance of exploitation in the next 30 days.

A vulnerability in the SNMP subsystem of Cisco IOS Software, Cisco IOS XE Software, and Cisco IOS XR Software could allow an authenticated, remote attacker to cause a DoS condition on an affected device. This vulnerability is due to improper error handling when parsing SNMP requests. An attacker could exploit this vulnerability by sending a crafted SNMP request to an affected device. For Cisco IOS and IOS XE Software, a successful exploit could allow the attacker to cause the device to reload unexpectedly, resulting in a DoS condition. For Cisco IOS XR Software, a successful exploit could allow the attacker to cause the SNMP process to restart, resulting in an interrupted SNMP response from an affected device. Devices that are running Cisco IOS XR Software will not reload.  This vulnerability affects SNMP versions 1, 2c, and 3. To exploit this vulnerability through SNMP v2c or earlier, the attacker must know a valid read-write or read-only SNMP community string for the affected system. To exploit this vulnerability through SNMP v3, the attacker must have valid SNMP user credentials for the affected system.

Affected products

• Cisco IOS: version 12.2(33)sre only; version 12.2(33)sre0a only; version 12.2(33)sre1 only; version 12.2(33)sre2 only; version 12.2(33)sre3 only; version 12.2(33)sre4 only; …
• Cisco IOS XE: version 3.2.0se only; version 3.2.1se only; version 3.2.2se only; version 3.2.3se only; version 3.3.0se only; version 3.3.0sg only; …
• Cisco IOS XR: version 7.0.1 only; version 7.0.2 only; version 7.0.12 only; version 7.0.14 only; version 7.1.1 only; version 7.1.2 only; …

Published 2025-02-05. Last modified 2026-06-17.