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CVE-2018-0156

High CVSS 7.5 Known exploited

Published 2018-03-28 · last changed 2026-06-17 · added to CISA KEV 2022-03-03

This one is being exploited in the wild.

CISA added CVE-2018-0156 to the Known Exploited Vulnerabilities catalog on 2022-03-03. Federal agencies are required to remediate it on a deadline. If you have affected machines, this is the class of finding that moves ahead of the rest of the queue.

The fix

We hold no Microsoft remediation data for CVE-2018-0156, which normally means it is not a Windows CVE. For non-Microsoft software the fix is the vendor's own updated release, and the affected versions are listed below.

What it is

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.

Sources

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