CVE-2017-12232: Cisco IOS Software for Cisco Integrated Services Routers Denial-of-Service Vulnerability

Medium severity, CVSS 6.5. Actively exploited: in CISA KEV since 2022-03-03. EPSS: 2.2% chance of exploitation in the next 30 days.

A vulnerability in the implementation of a protocol in Cisco Integrated Services Routers Generation 2 (ISR G2) Routers running Cisco IOS 15.0 through 15.6 could allow an unauthenticated, adjacent attacker to cause an affected device to reload, resulting in a denial of service (DoS) condition. The vulnerability is due to a misclassification of Ethernet frames. An attacker could exploit this vulnerability by sending a crafted Ethernet frame to an affected device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition. Cisco Bug IDs: CSCvc03809.

Affected products

• Cisco IOS: from 15.0, up to and including 15.6

Published 2017-09-29. Last modified 2026-06-17.