CVE DATABASE / CVE-2017-12237

CVE-2017-12237

Cisco IOS and IOS XE Software Internet Key Exchange Denial-of-Service Vulnerability

CVSS 7.5 · HIGH ⚠ CISA KEV — ACTIVELY EXPLOITED

On the CISA KEV catalog

Confirmed exploited in the wild. Added 2022-03-03. Federal remediation due 2022-03-24.
Required action: Apply updates per vendor instructions.

Summary

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.

CVSS 3.1 breakdown

Base score	7.5 (HIGH)
Vector	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector	NETWORK
Attack complexity	LOW
Privileges required	NONE
User interaction	NONE
Scope	UNCHANGED
Confidentiality	NONE
Integrity	NONE
Availability	HIGH

Weakness type (CWE)

CWE-399

Affected products

Cisco iosCisco ios xeCisco 1000 integrated services routerCisco 1100-4g\/6g integrated services routerCisco 1100-4g integrated services routerCisco 1100-4gltegb integrated services routerCisco 1100-4gltena integrated services routerCisco 1100-4p integrated services routerCisco 1100-6g integrated services routerCisco 1100-8p integrated services routerCisco 1100-lte integrated services routerCisco 1100 integrated services routerCisco 1101-4p integrated services routerCisco 1101 integrated services routerCisco 1109-2p integrated services routerCisco 1109-4p integrated services routerCisco 1109 integrated services routerCisco 1111x-8p integrated services routerCisco 1111x integrated services routerCisco 1120 integrated services router

Check this CVE live

Use our free CVE Lookup tool for the latest NVD record, or browse the full CISA KEV catalog.

References

Data: NIST NVD + CISA KEV. NVD last modified 2026-04-21. Always verify against the vendor advisory before acting.