cisco-sa-20180328-smi2: Cisco IOS and IOS XE Software Smart Install Remote Code Execution Vulnerability

Update August 20, 2025: Cisco is aware of continued exploitation activity of the vulnerability that is described in this advisory and strongly recommends that customers assess their systems and upgrade to a fixed software release as soon as possible.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 deviceAllowing the attacker to execute arbitrary code on the deviceCausing an indefinite loop on the affected device that triggers a watchdog crashCisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.Smart Install client functionality is enabled by default on switches that are running Cisco IOS Software releases that have not been updated to address Cisco bug ID CSCvd36820.This advisory is available at the following link:https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180328-smi2This advisory is part of the March 28, 2018, release of the Cisco IOS and IOS XE Software Security Advisory Bundled Publication, which includes 20 Cisco Security Advisories that describe 22 vulnerabilities. For a complete list of the advisories and links to them, see Cisco Event Response: March 2018 Semiannual Cisco IOS and IOS XE Software Security Advisory Bundled Publication.

— Cisco