Cisco · IOS and IOS XE Software
CVE-2017-12237
Cisco IOS and IOS XE Software Internet Key Exchange Denial-of-Service Vulnerability
What it is
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.
CISA: A vulnerability in the Internet Key Exchange Version 2 (IKEv2) module of Cisco IOS and Cisco IOS XE 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.
What to do
Apply updates per vendor instructions.
Deadline for US federal agencies: March 24, 2022
More exploited flaws from Cisco
| Added | Vulnerability | Product | Severity | Attack chance |
|---|---|---|---|---|
| Apr 19, 2023 | SNMP Remote Code Execution | IOS and IOS XE Software | High 8.8 | 21% |
| Mar 3, 2022 | IOS Software and Cisco IOS XE Software UDP Packet Processing Denial-of-Service | IOS and IOS XE Software | High 7.5 | 6.2% |
| Mar 3, 2022 | IOS Software and Cisco IOS XE Software Denial-of-Service | IOS and IOS XE Software | Medium 6.5 | 2.1% |
| Mar 3, 2022 | SNMP Remote Code Execution | IOS and IOS XE Software | High 8.8 | 70% |
| Mar 3, 2022 | SNMP Remote Code Execution | IOS and IOS XE Software | High 8.8 | 45% |
| Mar 3, 2022 | SNMP Remote Code Execution | IOS and IOS XE Software | High 8.8 | 11% |
| Mar 3, 2022 | SNMP Remote Code Execution | IOS and IOS XE Software | High 8.8 | 11% |
| Mar 3, 2022 | SNMP Remote Code Execution | IOS and IOS XE Software | High 8.8 | 11% |
Sources: Known Exploited Vulnerabilities (CISA, public domain), CVE records (cve.org) and EPSS (FIRST). The chance of attacks is the EPSS estimate that someone will try to exploit the flaw in the next 30 days.