CVE-2017-12234: Cisco IOS Software Common Industrial Protocol Request Denial-of-Service Vulnerability

High severity, CVSS 7.5. Actively exploited: in CISA KEV since 2022-03-03. EPSS: 7.1% chance of exploitation in the next 30 days.

Multiple vulnerabilities in the implementation of the Common Industrial Protocol (CIP) feature in Cisco IOS 12.4 through 15.6 could allow an unauthenticated, remote attacker to cause an affected device to reload, resulting in a denial of service (DoS) condition. The vulnerabilities are due to the improper parsing of crafted CIP packets destined to an affected device. An attacker could exploit these vulnerabilities by sending crafted CIP packets to be processed by 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: CSCvc43709.

Affected products

• Cisco IOS: from 12.4, up to and including 15.6

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