CVE-2021-1529: Cisco IOS XE

High severity, CVSS 7.8. EPSS: 0.3% chance of exploitation in the next 30 days.

A vulnerability in the CLI of Cisco IOS XE SD-WAN Software could allow an authenticated, local attacker to execute arbitrary commands with root privileges. The vulnerability is due to insufficient input validation by the system CLI. An attacker could exploit this vulnerability by authenticating to an affected device and submitting crafted input to the system CLI. A successful exploit could allow the attacker to execute commands on the underlying operating system with root privileges.

Affected products

• Cisco IOS XE: from 16.12, up to and including 17.0; from 17.2, before 17.2.3 (fixed in 17.2.3); from 17.3, before 17.3.4 (fixed in 17.3.4); from 17.4, before 17.4.2 (fixed in 17.4.2); from 17.5, before 17.5.1a (fixed in 17.5.1a); version 17.6.0 only
• Cisco IOS XE SD-WAN: from 17.2.1r

Published 2021-10-21. Last modified 2026-06-17.