CVE DATABASE / CVE-2018-0159

CVE-2018-0159

Cisco IOS and XE Software Internet Key Exchange Version 1 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 2022-03-17.
Required action: Apply updates per vendor instructions.

Summary

A vulnerability in the implementation of Internet Key Exchange Version 1 (IKEv1) functionality in Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause an affected device to reload, resulting in a denial of service (DoS) condition. The vulnerability is due to improper validation of specific IKEv1 packets. An attacker could exploit this vulnerability by sending crafted IKEv1 packets to an affected device during an IKE negotiation. A successful exploit could allow the attacker to cause an affected device to reload, resulting in a DoS condition. Cisco Bug IDs: CSCuj73916.

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-20

Affected products

Cisco iosCisco asr 901-12c-f-dCisco asr 901-12c-ft-dCisco asr 901-4c-f-dCisco asr 901-4c-ft-dCisco asr 901-6cz-f-aCisco asr 901-6cz-f-dCisco asr 901-6cz-ft-aCisco asr 901-6cz-ft-dCisco me 3600x-24cx-mCisco me 3600x-24fs-mCisco me 3600x-24ts-mCisco me 3800x-24fs-mCisco ios xe

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References

Data: NIST NVD + CISA KEV. NVD last modified 2026-01-14. Always verify against the vendor advisory before acting.