CVE-2018-0159VulnerabilityPublished 03/03/2022Updated 10/24/2026

CVE-2018-0159: Cisco IOS and XE Software Internet Key Exchange Version 1 Denial-of-Service Vulnerability

Affects Cisco IOS Software and Cisco IOS XE SoftwareSource CISA KEV

Severity

High

No CVSS score published yet

Exploitation: Actively exploited – in CISA KEV since 03/03/2022
KEV deadline: 03/17/2022
EPSS: 6.9% chance of exploitation in 30 days – higher than 94% of CVEs

What to do

CISA required action

Apply updates per vendor instructions.

nvd.nist.gov/vuln/detail/CVE-2018-0159 (opens in a new tab)

Description

CVE-2018-0159 is a denial-of-service vulnerability in the Internet Key Exchange Version 1 (IKEv1) implementation of Cisco IOS and IOS XE Software. An unauthenticated remote attacker can exploit this flaw to cause the affected device to reload, disrupting network operations. This vulnerability has been exploited in the wild. No specific affected versions or patch information is provided in the available data.

Summary

This vulnerability exists in the IKEv1 functionality of Cisco IOS and IOS XE Software. It allows an unauthenticated remote attacker to trigger a device reload, resulting in a denial-of-service condition. The vulnerability has been observed being exploited in the wild, indicating active threat usage. No detailed version or patch information is included in the provided data.

Impact

Successful exploitation causes the targeted Cisco device to reload unexpectedly, leading to a denial-of-service condition that disrupts network availability. The vulnerability can be triggered remotely without authentication, increasing its risk. It has been confirmed to be exploited in the wild, demonstrating real-world impact.

Mitigation

Patch status is not yet confirmed — check the Cisco vendor advisory for current remediation guidance. Until a patch is applied, consider limiting exposure of IKEv1 services to untrusted networks and applying any recommended workarounds from Cisco advisories.

Weaknesses

CWE-20Improper Input Validation (opens in a new tab)

What to do

Description

AnalysisAI-generated, updated 10/24/2026, 10:40:47 UTC

Weaknesses

References

Related threats