Proxmox Server Solutions Proxmox Virtual Environment up to 7.4/8.0 libpve-access-control tfa-challenge improper authorization

Summaryinfo

A vulnerability labeled as very critical has been found in Proxmox Server Solutions Proxmox Virtual Environment up to 7.4/8.0. Affected is an unknown function of the component libpve-access-control. Such manipulation of the argument tfa-challenge leads to improper authorization. This vulnerability only affects products that are no longer supported by the maintainer. This vulnerability is documented as CVE-2023-54391. The attack can be executed remotely. There is not any exploit available.

Detailsinfo

A vulnerability, which was classified as very critical, has been found in Proxmox Server Solutions Proxmox Virtual Environment up to 7.4/8.0. Affected by this issue is an unknown part of the component libpve-access-control. The manipulation of the argument tfa-challenge with an unknown input leads to a improper authorization vulnerability. Using CWE to declare the problem leads to CWE-285. The product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action. Impacted is confidentiality, integrity, and availability. CVE summarizes:

Proxmox Virtual Environment (VE) 7.0 through 8.0 contains an authentication bypass vulnerability in libpve-access-control before 8.0.4 that allows unauthenticated attackers to authenticate as any existing enabled user without a configured second factor by supplying an arbitrary tfa-challenge value in the API login endpoint. Attackers can send a POST request to the access ticket API endpoint with any value in the tfa-challenge parameter to completely skip password verification, gaining unauthorized access including to the root@pam account. All affected releases are end of life.

The advisory is available at forum.proxmox.com. This vulnerability is handled as CVE-2023-54391 since 09/01/2026. The exploitation is known to be easy. The attack may be launched remotely. No form of authentication is required for exploitation. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 09/02/2026). This vulnerability is assigned to T1548.002 by the MITRE ATT&CK project.

Upgrading to version 8.0.4 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2023-60613). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Vendor

• Proxmox Server Solutions

Name

• Proxmox Virtual Environment

Version

• 7.0
• 7.1
• 7.2
• 7.3
• 7.4
• 8.0

Support

• end of life

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

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Entryinfo

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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