CVE-2018-0172

Name: CVE-2018-0172
Creator: NVD / NIST
Published: 2018-03-28T22:29:01.11+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 8.6/10Actively ExploitedEPSS 7.82%

Last modified Jun 17, 2026

CVE-2018-0172 is a high-severity vulnerability rated 8.6/10 on the CVSS scale. 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. CISA has confirmed active exploitation in the wild. EPSS estimates a 7.82% chance of exploitation in the next 30 days.

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 a heap overflow condition on the affected device, which will cause the device to reload and result in a DoS condition. Cisco Bug IDs: CSCvg62730.

Metrics

CVSS 3.1

8.6/10

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

EPSS Probability

7.82%

93.9th percentile

Probability of exploitation in the next 30 days. Learn more

Exploitation Status

This vulnerability is listed in CISA’s Known Exploited Vulnerabilities catalog, confirming active exploitation in the wild. Federal agencies must remediate by Mar 17, 2022.

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Cisco	Ios	All versions
Cisco	Ios Xe	All versions

References

http://www.securityfocus.com/bid/103552Third Party Advisory, VDB Entry
http://www.securitytracker.com/id/1040591Third Party Advisory, VDB Entry
https://ics-cert.us-cert.gov/advisories/ICSA-18-107-04Third Party Advisory, US Government Resource
https://ics-cert.us-cert.gov/advisories/ICSA-18-107-05Third Party Advisory, US Government Resource
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180328-dhcpr1Vendor Advisory
https://www.tenable.com/security/research/tra-2018-06Third Party Advisory
http://www.securityfocus.com/bid/103552Third Party Advisory, VDB Entry
http://www.securitytracker.com/id/1040591Third Party Advisory, VDB Entry
https://ics-cert.us-cert.gov/advisories/ICSA-18-107-04Third Party Advisory, US Government Resource
https://ics-cert.us-cert.gov/advisories/ICSA-18-107-05Third Party Advisory, US Government Resource
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180328-dhcpr1Vendor Advisory
https://www.tenable.com/security/research/tra-2018-06Third Party Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2018-0172US Government Resource

Timeline

Published: Mar 28, 2018
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2018-0172?

How severe is CVE-2018-0172?

CVE-2018-0172 has a CVSS score of 8.6/10 (HIGH severity). The EPSS model estimates a 7.82% probability of exploitation in the next 30 days. This vulnerability is listed in CISA's Known Exploited Vulnerabilities catalog.

How do I fix CVE-2018-0172?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2018-0172?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST