Cisco fixes a critical flaw in Enterprise NFVIS for which PoC exploit exists

Cisco released patches for a critical authentication bypass issue in Enterprise NFV Infrastructure Software (NFVIS) for which PoC exploit code is available.

Cisco announced the availability of security patches for a critical authentication bypass flaw (CVE-2021-34746) in Enterprise NFV Infrastructure Software (NFVIS) for which proof-of-concept exploit code is already available. An attacker can exploit the issue to bypass authentication and log in as an administrator to the affected device.

By virtualizing and abstracting the network services from the underlying hardware, NFVIS allows virtual network functions (VNFs) to be managed independently and to be provisioned dynamically.

The CVE-2021-34746 flaw was reported by Orange Group security researcher Cyrille Chatras, the issue received a CVSS score of 9.8.

The vulnerability affects the TACACS+ authentication, authorization and accounting (AAA) feature of Enterprise NFVIS, it is due to incomplete validation of user-supplied input when it is passed to an authentication script. Cisco pointed out that there are no workarounds that address this vulnerability.

“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.” reads the advisory published by Cisco. “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.”

The vulnerability affects Enterprise NFVIS release 4.5.1 only if the TACACS external authentication method is configured, Cisco fixed it with Enterprise NFVIS releases 4.6.1.

The good news is that Cisco is not aware of attacks in the wild exploit this flaw.

Follow me on Twitter: @securityaffairs and Facebook

[adrotate banner=”9″]

[adrotate banner=”12″]

Pierluigi Paganini

(SecurityAffairs – hacking, FIN8)

[adrotate banner=”5″]

[adrotate banner=”13″]

Pierluigi Paganini

Pierluigi Paganini is member of the ENISA (European Union Agency for Network and Information Security) Threat Landscape Stakeholder Group and Cyber G7 Group, he is also a Security Evangelist, Security Analyst and Freelance Writer. Editor-in-Chief at "Cyber Defense Magazine", Pierluigi is a cyber security expert with over 20 years experience in the field, he is Certified Ethical Hacker at EC Council in London. The passion for writing and a strong belief that security is founded on sharing and awareness led Pierluigi to find the security blog "Security Affairs" recently named a Top National Security Resource for US. Pierluigi is a member of the "The Hacker News" team and he is a writer for some major publications in the field such as Cyber War Zone, ICTTF, Infosec Island, Infosec Institute, The Hacker News Magazine and for many other Security magazines. Author of the Books "The Deep Dark Web" and “Digital Virtual Currency and Bitcoin”.