CVE-2021-34729: A vulnerability in the CLI of Cisco IOS XE SD-WAN Software and Cisco IOS XE Software could allow an authenticated, local attacker to execute arbitrary...

Description

A vulnerability in the CLI of Cisco IOS XE SD-WAN Software and Cisco IOS XE Software could allow an authenticated, local attacker to execute arbitrary commands with elevated privileges on an affected device. This vulnerability is due to insufficient validation of arguments passed to certain CLI commands. An attacker could exploit this vulnerability by including malicious input in the argument of an affected command. A successful exploit could allow the attacker to execute arbitrary commands with elevated privileges on the underlying operating system. An attacker would need valid user credentials to exploit this vulnerability.

Metrics

CVSS 3.1

6.7/10

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

EPSS Probability

0.35%

26.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Cisco	Ios Xe	<= 17.3.1a
Cisco	Ios Xe Sd-Wan	<= 17.3.1a

References

Timeline

Published: Sep 23, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-34729?

A vulnerability in the CLI of Cisco IOS XE SD-WAN Software and Cisco IOS XE Software could allow an authenticated, local attacker to execute arbitrary commands with elevated privileges on an affected device. This vulnerability is due to insufficient validation of arguments passed to certain CLI commands. An attacker could exploit this vulnerability by including malicious input in the argument of an affected command. A successful exploit could allow the attacker to execute arbitrary commands with elevated privileges on the underlying operating system. An attacker would need valid user credentials to exploit this vulnerability.

How severe is CVE-2021-34729?

CVE-2021-34729 has a CVSS score of 6.7/10 (MEDIUM severity). The EPSS model estimates a 0.35% probability of exploitation in the next 30 days.

How do I fix CVE-2021-34729?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.