Proxmox VE 7.0-8.0 Authentication Bypass via tfa-challenge Parameter
Proxmox Server Solutions GmbH · Proxmox Virtual Environment (VE)
The authentication flaw is in libpve-access-control before 8.0.4, a component of Proxmox Virtual Environment (VE) versions 7.0 through 8.0, where the login handling wrongly lets a request bypass password verification. An unauthenticated remote attacker who sends a POST request to the access ticket API endpoint with an arbitrary value in the tfa-challenge parameter can log in as any existing enabled user that has no second factor configured, including root@pam, with no password, no prior authentication, and no user interaction required.
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.
- Exploited
- Yes, in VulnCheck KEV
- Reports
- 0
- Tactics
- 0/15
Exploitation timelineDated milestones for a CVE: when it was disclosed, when exploit code became public, when exploitation was confirmed, and when threat reports named it.
First seen exploited the day it was disclosed. Public exploit code (PoC-in-GitHub) appeared 2 days after disclosure.
- Public exploit codePoC-in-GitHub+2 days
MITRE ATT&CKA public catalogue of the techniques attackers use, maintained by MITRE. Patchfirst uses it to describe what attackers do with a vulnerability. techniques
No techniques linkedNo ATT&CK techniques are linked to this CVE yet. MITRE CTID has not mapped it, and no report passage in the corpus ties it to a technique.
What security researchers reported
Not named in any threat report yetAlso mentioned in 2 community threat pulses (AlienVault OTX)
Weaker evidencePulses are indicator collections that anyone can publish. A mention is not confirmation of exploitation.