CVE-2017-12232 Cisco IOS Software for Cisco Integrated Services Routers Denial-of-Service

Exploited in the wild Medium 6.5 Published 28 Sep 2017 Updated 12 Jan 2026

An unauthenticated adjacent attacker can cause a Cisco ISR G2 router to reload by sending a crafted Ethernet frame, resulting in a denial of service.

Exploited in the wild: Since 3 Mar 2022
Login needed: Not needed
Attackable: Local or same network only
Victim action needed: Not needed
Fix: None listed

What is CVE-2017-12232?

CVE-2017-12232 is a medium-severity denial of service vulnerability in Cisco Ios, published on 28 Sep 2017. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

A vulnerability in the implementation of a protocol in Cisco Integrated Services Routers Generation 2 (ISR G2) Routers running Cisco IOS 15.0 through 15.6 could allow an unauthenticated, adjacent attacker to cause an affected device to reload, resulting in a denial of service (DoS) condition. The vulnerability is due to a misclassification of Ethernet frames. An attacker could exploit this vulnerability by sending a crafted Ethernet frame to an affected device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition. Cisco Bug IDs: CSCvc03809.

Weakness: CWE-399

Which versions are affected by CVE-2017-12232?

It affects 1 product.

Products include Cisco Ios.

How do I fix CVE-2017-12232?

No fix has been published for CVE-2017-12232 yet. Limit exposure of the affected software until one is available. US federal agencies must fix it by 24 Mar 2022.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2017-12232 being exploited?

Yes. Attackers have exploited CVE-2017-12232 in the wild since at least 3 Mar 2022.

All Cisco Ios vulnerabilities

Sources

Also known as GHSA-j4ww-r9hh-57hx.