CVE-2021-34746

Name: CVE-2021-34746
Creator: NVD / NIST
Published: 2021-09-02T03:15:06.687+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 17.66%

Last modified Jun 17, 2026

CVE-2021-34746 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. A vulnerability in the TACACS+ authentication, authorization and accounting (AAA) feature of Cisco Enterprise NFV Infrastructure Software (NFVIS) could allow an unauthenticated, remote attacker to bypass authentication and log in to an affected device as an administrator. This vulnerability is due to incomplete validation of user-supplied input that is passed to an authentication script. EPSS estimates a 17.66% chance of exploitation in the next 30 days.

Description

A vulnerability in the TACACS+ authentication, authorization and accounting (AAA) feature of Cisco Enterprise NFV Infrastructure Software (NFVIS) could allow an unauthenticated, remote attacker to bypass authentication and log in to an affected device as an administrator. This vulnerability is due to incomplete validation of user-supplied input that is passed to an authentication script. An attacker could exploit this vulnerability by injecting parameters into an authentication request. A successful exploit could allow the attacker to bypass authentication and log in as an administrator to the affected device.

Metrics

CVSS 3.1

9.8/10

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

EPSS Probability

17.66%

96.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Cisco	Enterprise Nfv Infrastructure Software	< 4.6.1

References

https://github.com/orangecertcc/security-research/security/advisories/GHSA-gqx8-c4xr-c664Exploit, Third Party Advisory
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-nfvis-g2DMVVhVendor Advisory
https://github.com/orangecertcc/security-research/security/advisories/GHSA-gqx8-c4xr-c664Exploit, Third Party Advisory
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-nfvis-g2DMVVhVendor Advisory

Timeline

Published: Sep 2, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-34746?

How severe is CVE-2021-34746?

CVE-2021-34746 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 17.66% probability of exploitation in the next 30 days.

How do I fix CVE-2021-34746?

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.

Are you affected by CVE-2021-34746?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST