---
id: "CVE-2017-12234"
kind: "vulnerability"
aliases: ["CVE-2017-12234"]
title: "Cisco IOS software: Cisco IOS Software Common Industrial Protocol Request Denial-of-Service Vulnerability"
severity: "high"
cvss: 7.8
epss: 0.0707
exploited: true
status: "open"
category: "infrastructure"
products: [{"name": "Cisco IOS software", "fixed": [], "affected": "", "ecosystem": "vendor"}]
ecosystems: ["vendor"]
tags: ["cisco", "exploited", "industrial-control", "infrastructure", "ios", "network-gear"]
not_affected_if: ["cip-disabled", "default-config"]
published_at: "2017-09-29T01:34:48+00:00"
first_seen_at: "2026-10-23T19:11:52+00:00"
updated_at: "2026-10-23T21:57:35+00:00"
sources: [{"source": "kev", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2017-12234", "first_seen_at": "2026-10-23T19:11:52+00:00"}, {"source": "epss", "url": "https://api.first.org/data/v1/epss?cve=CVE-2017-12234", "first_seen_at": "2026-10-23T19:13:44+00:00"}, {"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2017-12234", "first_seen_at": "2026-10-23T21:57:35+00:00"}]
---

# Cisco IOS software: Cisco IOS Software Common Industrial Protocol Request Denial-of-Service Vulnerability

Cisco IOS software has a flaw in its Common Industrial Protocol (CIP) handling that lets an unauthenticated remote attacker reload the device. The result is a denial of service, and the flaw is listed as actively exploited.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- vendor:Cisco IOS software affected ? fixed ?

## How to check

Run 'show running-config | include cip' on the device to see whether CIP is enabled; unknown for the exact affected versions.

## Fix

Apply the Cisco IOS update per vendor instructions; the fixed version is unknown from the sources.
Disable CIP if it is not needed; unknown whether this is the vendor's recommended workaround.

## Timeline

- 2026-10-23T19:11:52+00:00 kev https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2017-12234
- 2026-10-23T19:13:44+00:00 epss https://api.first.org/data/v1/epss?cve=CVE-2017-12234
- 2026-10-23T21:57:35+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2017-12234

## From the sources

Multiple vulnerabilities in the implementation of the Common Industrial Protocol (CIP) feature in Cisco IOS 12.4 through 15.6 could allow an unauthenticated, remote attacker to cause an affected device to reload, resulting in a denial of service (DoS) condition. The vulnerabilities are due to the improper parsing of crafted CIP packets destined to an affected device. An attacker could exploit these vulnerabilities by sending crafted CIP packets to be processed by 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: CSCvc43709.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_