CVE-2018-0156: Cisco IOS Software and Cisco IOS XE Software Smart Install Denial-of-Service Vulnerability

CISA Known Exploited Vulnerabilities

Name

Cisco IOS Software and Cisco IOS XE Software Smart Install Denial-of-Service Vulnerability

Vendor

Cisco

Product

IOS Software and Cisco IOS XE Software

Added to the catalog

2022-03-03

Due date for US federal agencies

2022-03-17

Weaknesses

CWE-399

Catalog version

2026.10.30

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.

Required action (CISA)

Apply updates per vendor instructions.

Ransomware use: CISA does not mark known use of this vulnerability in ransomware campaigns.

Links in CISA's notes

• https://nvd.nist.gov/vuln/detail/CVE-2018-0156

Read on 2026-11-02T23:39:54.475Z under licence cisa-kev-cc0@b0067899 from https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json

NVD analysis

Status

Analyzed

Published

2018-03-28T22:29:00.467

Last modified

2026-06-17T01:29:57.570

Weaknesses

CWE-399, CWE-20

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. The vulnerability is due to improper validation of packet data. An attacker could exploit this vulnerability by sending a crafted packet to an affected device on TCP port 4786. Only Smart Install client switches are affected. Cisco devices that are configured as a Smart Install director are not affected by this vulnerability. Cisco Bug IDs: CSCvd40673.

References

• http://www.securityfocus.com/bid/103569 (Third Party Advisory, VDB Entry)
• http://www.securitytracker.com/id/1040596 (Third Party Advisory, VDB Entry)
• https://ics-cert.us-cert.gov/advisories/ICSA-18-107-04 (Third Party Advisory, US Government Resource)
• https://ics-cert.us-cert.gov/advisories/ICSA-18-107-05 (Third Party Advisory, US Government Resource)
• https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180328-smi (Vendor Advisory)
• http://www.securityfocus.com/bid/103569 (Third Party Advisory, VDB Entry)
• http://www.securitytracker.com/id/1040596 (Third Party Advisory, VDB Entry)
• https://ics-cert.us-cert.gov/advisories/ICSA-18-107-04 (Third Party Advisory, US Government Resource)
• https://ics-cert.us-cert.gov/advisories/ICSA-18-107-05 (Third Party Advisory, US Government Resource)
• https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180328-smi (Vendor Advisory)
• https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2018-0156 (US Government Resource)

This product uses the NVD API but is not endorsed or certified by the NVD.

Read on 2026-11-02T23:41:35.381Z under licence nvd-api-terms-of-use@ff2a5288 from https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2018-0156

CVE record

Assigner

cisco

State

PUBLISHED

Published

2018-03-28T22:00:00.000Z

Updated

2026-01-12T21:54:00.542Z

Problem types

CWE-399

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. The vulnerability is due to improper validation of packet data. An attacker could exploit this vulnerability by sending a crafted packet to an affected device on TCP port 4786. Only Smart Install client switches are affected. Cisco devices that are configured as a Smart Install director are not affected by this vulnerability. Cisco Bug IDs: CSCvd40673.

References

• https://ics-cert.us-cert.gov/advisories/ICSA-18-107-04
• https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180328-smi
• 1040596
• 103569
• https://ics-cert.us-cert.gov/advisories/ICSA-18-107-05

Read on 2026-11-03T00:35:53.978Z under licence cve-terms-of-use@81bfa2f3 from https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2018/0xxx/CVE-2018-0156.json

Defensive techniques (MITRE D3FEND)

D3FEND maps these defensive techniques to the weakness (CWE) that NVD lists for this CVE, through the digital artifacts the weakness affects. D3FEND does not say they stop this vulnerability.

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