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CVE-2018-0174

8.6, high Known exploited

Cisco IOS Software and Cisco IOS XE Software Improper Input Validation Vulnerability

NVD (opens in a new tab) CVE.org (opens in a new tab) CISA KEV catalogue (opens in a new tab)
CVSS
8.6, high high CVSS v3.1
EPSS, next 30 days
8% higher than 94.4% of scored CVEs
Exploitation
Confirmed in the wild
Published
28 Mar 20188 years ago

Known exploited

CISA added this to the Known Exploited Vulnerabilities Catalog on 3 Mar 2022. US federal agencies had to remediate by 17 Mar 2022, a deadline that has passed.

Required action. Apply updates per vendor instructions.

Description

A vulnerability in the DHCP option 82 encapsulation functionality of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause an affected device to reload, resulting in a denial of service (DoS) condition. The vulnerability exists because the affected software performs incomplete input validation of option 82 information that it receives in DHCP Version 4 (DHCPv4) packets from DHCP relay agents. An attacker could exploit this vulnerability by sending a crafted DHCPv4 packet 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: CSCuh91645.

Details

Vendor
Cisco and 1 more
Product
Cisco IOS and IOS XE
Weakness
CWE-20 (opens in a new tab)
Status
Analyzed
Updated
17 Jun 2026
Assigner
psirt@cisco.com

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

References 7

Advisories 6

Other references 1

The kind is read from NVD's tags where present and from the shape of the URL otherwise, so treat it as a hint.

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Beyond this page

Is CVE-2018-0174 in your network?

This page tells you how dangerous CVE-2018-0174 is out there. Whether it sits on one of your devices, only a scan of your own network can tell. That is what our systems do, every day, for the companies we protect.

CVE-2018-0174 is in the CISA catalogue of exploited vulnerabilities: attackers are already exploiting it.

  • EXYS7600 OCELOT

    Find it before attackers do

    Ocelot scans your network on a schedule and reports every vulnerability it finds by its CVE identifier, with its CVSS score and how many of your hosts are affected. A finding like CVE-2018-0174 comes with the devices to patch.

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  • EXYS7950 KONDRA

    Detect it if it's exploited

    Until the patch is applied, Kondra monitors your network, events and endpoints in real time. It keeps an inventory of the software installed on every endpoint, and its anomaly detection rules flag what an attacker does once inside.

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Check your exposure

Assembled from the NVD 2.0 API, the CISA Known Exploited Vulnerabilities Catalog and FIRST EPSS. Scores are as of our last collection on 16 Oct 2026, not the live upstream state.