CVE-2018-0159
HighExploitedPublic exploitA 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.
Published Mar 28, 2018 · Updated Jan 14, 2026
Key Facts
Patch immediately- CVE-2018-0159 is a high-severity vulnerability (CVSS 7.5 v3.1) affecting IOS (Cisco), IOS Xe (Cisco), Cisco IOS and IOS XE.
- It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Mar 3, 2022. Public exploit code is available.
- EPSS estimates a 6.9% probability of exploitation in the next 30 days.
- No fixed version is listed yet; check the vendor advisory for mitigations.
- Brandefense priority: patch immediately, because it is listed as exploited in the wild.
CVSS v3.1
7.5
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS (30-day exploit likelihood)
6.9%
Higher than 93.9% of all scored CVEs
Exploited in the wild
Yes
4 catalog listings
Public exploit code
Available
Proof-of-concept or weaponized module
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Description
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.
Known-Exploited Catalog Listings
| Catalog | Added | Remediation due | Ransomware use |
|---|---|---|---|
| CISA KEV | Mar 3, 2022 | Mar 17, 2022 | Not reported |
| Industry KEV feed | Mar 3, 2022 | Mar 17, 2022 | Not reported |
| CIRCL KEV | Mar 3, 2022 | Mar 17, 2022 | Not reported |
| ENISA EUVD | Mar 3, 2022 | n/a | Not reported |
Required action: Apply updates per vendor instructions.
Affected Products
3 affected entries in total| Product | Affected versions | Fixed in |
|---|---|---|
| IOSCisco | 15.3\(3\)s | n/a |
| IOS XeCisco | 15.3\(3\)s | n/a |
| Cisco IOS and IOS XE | >= Cisco IOS and IOS XE | n/a |
Timeline
Publicly disclosed
Mar 28, 2018
Added to CISA KEV
Mar 3, 2022
Added to Industry KEV feed
Mar 3, 2022
Added to CIRCL KEV
Mar 3, 2022
Added to ENISA EUVD
Mar 3, 2022
Last updated
Jan 14, 2026
Weakness Type
- CWE-20 Improper Input Validation
References
- advisoryhttps://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180328-ike-dos
- advisory103562
- advisory1040595
- exploitVulnCheck exploitation report
- exploitVulnCheck exploitation report
FAQ
Common Questions.
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.
Affected: IOS (Cisco) versions 15.3\(3\)s; IOS Xe (Cisco) versions 15.3\(3\)s; Cisco IOS and IOS XE versions >= Cisco IOS and IOS XE. The full list is in the CVE brief.
It is exploited in the wild, listed in CISA KEV, Industry KEV feed, CIRCL KEV, ENISA EUVD since Mar 3, 2022.
Yes. It was added on Mar 3, 2022 with a federal remediation due date of Mar 17, 2022.
Public exploit code is available.
No fixed version is listed yet; check the vendor advisory for mitigations.
Brandefense priority: patch immediately, because it is listed as exploited in the wild.
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