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

High severity, CVSS 7.5. Actively exploited: in CISA KEV since 2022-03-03. EPSS: 9.4% chance of exploitation in the next 30 days.

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.

Affected products

• Cisco IOS: version 15.2(2)e4 only; version 15.2(2a)ja only
• Cisco IOS XE: version 15.2(2)e4 only; version 15.2(2a)ja only

Published 2018-03-28. Last modified 2026-06-17.