Skip to main content
ExploitedIn CISA KEV

CVE-2017-12237

Exploitation confirmed. First attested on 2022-03-03 by CISA-ADP, CISA KEV, GCVE · kevintel.

  • Published2017-09-29
  • WeaknessCWE-399

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

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.

Timeline

dates in UTC
  1. 2017-09-2901:34CVE publishedNVD
  2. 2022-03-03Added to the CISA KEV catalogCISA KEV
  3. 2022-03-03Listed as exploited by GCVEGCVE
  4. 2022-03-03Exploitation first reportedCISA KEV
  5. 2024-11-0817:32SSVC exploitation set to activeCISA-ADP

Observed activity

isMalicious corpus · updated 2026-10-23 21:37 UTC
Indicators tagged with this CVE, per day0 indicators over 7 days
Block these indicators
  • Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2017-12237?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2017-12237?format=csv
  • TAXII collection of exploited CVEs
  • The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD
Cisco iosversion to verify
BranchAffectedFixed in
15.x≥ 15.0, ≤ 15.6no fix published
Cisco ios xeversion to verify
BranchAffectedFixed in
16.5≥ 3.5.0e, ≤ 16.5no fix published

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

  1. CISA’s required action: Apply updates per vendor instructions.due 2022-03-24

Advisories and patches

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof-of-concept repositories
none listed
PoC-in-GitHub

CISA Known Exploited Vulnerability

Date Added
2022-03-03
Patch Due Date
2022-03-24
Ransomware Use
Unknown
Required Action
Apply updates per vendor instructions.

Sources

  • CISA KEVKEV entry2022-03-03
  • GCVEexploitation2022-03-03
  • CISA-ADPSSVC decisionactive2024-11-08
  • OpenCVESSVC decisionactive—
  • CISA-ADPCVSS 3.17.52024-11-08
  • NVDCVSS 3.17.5read 2026-10-23
  • NVDCVSS 2.07.8read 2026-10-23
  • CNAweakness (CWE)CWE-399read 2026-10-23
  • FIRST EPSSEPSS score7.1 %2026-10-22

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Published
2017-09-29
Last Modified
2026-06-17
NVD status
Analyzed

Frequently asked questions

What is CVE-2017-12237?

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.

Is CVE-2017-12237 actively exploited?

Yes. CVE-2017-12237 is on the CISA Known Exploited Vulnerabilities (KEV) catalog, meaning it has been confirmed as actively exploited in the wild. CISA requires federal agencies to patch by 2022-03-24.

What is the CVSS score for CVE-2017-12237?

CVE-2017-12237 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Hear about the next vulnerability in your software

Surveillance reads the versions in your stack — a domain, a lockfile or a list — checks each CVE against the ranges its sources publish, and alerts you when one you run is exploited or enters CISA KEV. A version it cannot read stays « version not verified ».

No credit card required · No monthly cap on website lookups · 250 API requests/month