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CRITICAL

CVE-2021-34746

CVSS v3

9.8

CRITICAL

EPSS Score

17.7 %

exploit probability, as of 2026-10-19

CISA KEV

No

known exploited

Exploitation

—

SSVC status

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Affected and fixed versions

Neither OSV.dev nor the vendor advisories we read list affected versions for CVE-2021-34746 yet.

Full record on NVD

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.

Technical details

Published
2021-09-02

Frequently asked questions

What is CVE-2021-34746?

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.

Is CVE-2021-34746 actively exploited?

Active exploitation of CVE-2021-34746 has not been confirmed. Its EPSS score was 17.7% on 2026-10-19, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2021-34746?

CVE-2021-34746 has a CVSS v3 base score of 9.8 (CRITICAL severity).

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