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CVE-2017-12237

High 7.5 Exploited in the wild (KEV)

Confirmed active exploitation — CISA KEV catalog

Name
Cisco IOS and IOS XE Software Internet Key Exchange Denial-of-Service Vulnerability
Added to catalog
Remediation due date (US federal)
Required action
Apply updates per vendor instructions.

Description

A vulnerability in the Internet Key Exchange Version 2 (IKEv2) module of Cisco IOS 15.0 through 15.6 and Cisco IOS XE 3.5 through 16.5 could allow an unauthenticated, remote attacker to cause high CPU utilization, traceback messages, or a reload of an affected device that leads to a denial of service (DoS) condition. The vulnerability is due to how an affected device processes certain IKEv2 packets. An attacker could exploit this vulnerability by sending specific IKEv2 packets to an affected device to be processed. A successful exploit could allow the attacker to cause high CPU utilization, traceback messages, or a reload of the affected device that leads to a DoS condition. This vulnerability affects Cisco devices that have the Internet Security Association and Key Management Protocol (ISAKMP) enabled. Although only IKEv2 packets can be used to trigger this vulnerability, devices that are running Cisco IOS Software or Cisco IOS XE Software are vulnerable when ISAKMP is enabled. A device does not need to be configured with any IKEv2-specific features to be vulnerable. Many features use IKEv2, including different types of VPNs such as the following: LAN-to-LAN VPN; Remote-access VPN, excluding SSL VPN; Dynamic Multipoint VPN (DMVPN); and FlexVPN. Cisco Bug IDs: CSCvc41277.

Metrics

CVSS 3.1
7.5 (HIGH) Score source: NVD CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS — exploit probability
7% (percentile: 94) as of 1 November 2026
CWE
CWE-399

Affected products

cisco: ios; cisco: ios xe; cisco: 1000 integrated services router; cisco: 1100-4g\/6g integrated services router; cisco: 1100-4g integrated services router; cisco: 1100-4gltegb integrated services router; cisco: 1100-4gltena integrated services router; cisco: 1100-4p integrated services router; cisco: 1100-6g integrated services router; cisco: 1100-8p integrated services router; cisco: 1100-lte integrated services router; cisco: 1100 integrated services router; cisco: 1101-4p integrated services router; cisco: 1101 integrated services router; cisco: 1109-2p integrated services router

References