CVE-2018-0171

Name: CVE-2018-0171
Creator: NVD / NIST
Published: 2018-03-28T22:29:01.063+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10Actively ExploitedEPSS 99.51%

Last modified Jun 17, 2026

CVE-2018-0171 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. A vulnerability in the Smart Install feature of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to trigger a reload of an affected device, resulting in a denial of service (DoS) condition, or to execute arbitrary code on an affected device. The vulnerability is due to improper validation of packet data. CISA has confirmed active exploitation in the wild. EPSS estimates a 99.51% chance of exploitation in the next 30 days.

Description

A vulnerability in the Smart Install feature of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to trigger a reload of an affected device, resulting in a denial of service (DoS) condition, or to execute arbitrary code on an affected device. The vulnerability is due to improper validation of packet data. An attacker could exploit this vulnerability by sending a crafted Smart Install message to an affected device on TCP port 4786. A successful exploit could allow the attacker to cause a buffer overflow on the affected device, which could have the following impacts: Triggering a reload of the device, Allowing the attacker to execute arbitrary code on the device, Causing an indefinite loop on the affected device that triggers a watchdog crash. Cisco Bug IDs: CSCvg76186.

Metrics

CVSS 3.1

9.8/10

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

EPSS Probability

99.51%

99.9th 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 May 3, 2022.

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Cisco	Ios	15.2\(5\)e

References

http://www.securityfocus.com/bid/103538Third Party Advisory, VDB Entry
http://www.securitytracker.com/id/1040580Third 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-smi2Vendor Advisory
https://www.darkreading.com/perimeter/attackers-exploit-cisco-switch-issue-as-vendor-warns-of-yet-another-critical-flaw/d/d-id/1331490Press/Media Coverage
http://www.securityfocus.com/bid/103538Third Party Advisory, VDB Entry
http://www.securitytracker.com/id/1040580Third 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-smi2Vendor Advisory
https://www.darkreading.com/perimeter/attackers-exploit-cisco-switch-issue-as-vendor-warns-of-yet-another-critical-flaw/d/d-id/1331490Press/Media Coverage
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2018-0171US Government Resource

Timeline

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

Frequently Asked Questions

What is CVE-2018-0171?

How severe is CVE-2018-0171?

CVE-2018-0171 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 99.51% probability of exploitation in the next 30 days. This vulnerability is listed in CISA's Known Exploited Vulnerabilities catalog.

How do I fix CVE-2018-0171?

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-2018-0171?

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

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Source: NVD / NIST