---
id: "CVE-2018-0154"
kind: "vulnerability"
aliases: ["CVE-2018-0154"]
title: "Cisco IOS Software: Cisco IOS Software Integrated Services Module for VPN 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", "infrastructure", "ios", "network-appliance"]
not_affected_if: ["no-ism-vpn-module", "non-ios-platform"]
published_at: "2018-03-28T22:29:00+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-2018-0154", "first_seen_at": "2026-10-23T19:11:52+00:00"}, {"source": "epss", "url": "https://api.first.org/data/v1/epss?cve=CVE-2018-0154", "first_seen_at": "2026-10-23T19:13:44+00:00"}, {"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2018-0154", "first_seen_at": "2026-10-23T21:57:35+00:00"}]
---

# Cisco IOS Software: Cisco IOS Software Integrated Services Module for VPN Denial-of-Service Vulnerability

A flaw in the crypto engine of Cisco's Integrated Services Module for VPN (ISM-VPN) running Cisco IOS Software lets a remote, unauthenticated attacker crash the device with a denial-of-service condition. The attacker gets an outage, not code execution or data access.

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

## Affected

- vendor:Cisco IOS Software affected ? fixed ?

## Fix

Apply the Cisco IOS Software update per the vendor advisory (CISA's required action is 'apply updates per vendor instructions'); the fixed version is unknown from these sources.

## Timeline

- 2026-10-23T19:11:52+00:00 kev https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2018-0154
- 2026-10-23T19:13:44+00:00 epss https://api.first.org/data/v1/epss?cve=CVE-2018-0154
- 2026-10-23T21:57:35+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2018-0154

## From the sources

A vulnerability in the crypto engine of the Cisco Integrated Services Module for VPN (ISM-VPN) running Cisco IOS Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to insufficient handling of VPN traffic by the affected device. An attacker could exploit this vulnerability by sending crafted VPN traffic to an affected device. A successful exploit could allow the attacker to cause the affected device to hang or crash, resulting in a DoS condition. Cisco Bug IDs: CSCvd39267.

---

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