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.

libpvestorage-perl v9.1.1 and libpve-storage-perl v8.3.7 were discovered to contain an XML External Entity (XXE) vulnerability.

Incorrect access control in Proxmox Virtual Environment (PVE) 9.x qemu-server before 9.1.8 and 8.x before 8.4.8 allows users within limited privileges to obtain hashed passwords via the cloudinit/dump API.

A cross-site scripting (XSS) vulnerability in Proxmox Virtual Environment (PVE) 9.x 5.1.8 and Proxmox Virtual Environment (PVE) 8.x 4.3.16 allows attackers to execute arbitrary web scripts or HTML via injecting a crafted payload.

A race condition between the vncproxy and vncwebsocket API calls in Proxmox Virtual Environment (PVE) 9.x pve-manager before 9.1.9 and 8.x before 8.4.19; qemu-server 9.x before 9.1.7 and 8.x before 8.4.7; and pve-container before 6.1.3 (PVE 9.x) and before 5.3.4 (PVE 8.x) allows an attacker with privileges to call "vncproxy" to hijack a VNC session that is established in parallel by a different user for a different VM.

A stored cross-site scripting (XSS) vulnerability exists in the WebAuthn Relying Party field within the Datacenter configuration of Proxmox Virtual Environment (PVE) 8.4. Authenticated users can inject JavaScript code that is later executed in the browsers of users who view the configuration page, enabling client-side attacks.

A stored cross-site scripting (XSS) vulnerability in the HTTP Proxy field within the Datacenter configuration panel of Proxmox Virtual Environment (PVE) 8.4 allows an authenticated user to inject malicious input. The input is stored and executed in the context of other users' browsers when they view the affected configuration page. This can lead to arbitrary JavaScript execution.

A stored cross-site scripting (XSS) vulnerability in the U2F Origin field of the Datacenter configuration in Proxmox Virtual Environment (PVE) 8.4 allows authenticated users to store malicious input. The payload is rendered unsafely in the Web UI and executed when viewed by other users, potentially leading to session hijacking or other attacks.

Proxmox Virtual Environment is an open-source server management platform for enterprise virtualization. Insufficient safeguards against malicious API response values allow authenticated attackers with 'Sys.Audit' or 'VM.Monitor' privileges to download arbitrary host files via the API. When handling the result from a request handler before returning it to the user, the handleapi2request function will check for the ‘download’ or ‘data’->’download’ objects inside the request handler call response object. If present, handleapi2request will read a local file defined by this object and return it to the user. Two endpoints were identified which can control the object returned by a request handler sufficiently that the ’download’ object is defined and user controlled. This results in arbitrary file read. The privileges of this file read can result in full compromise of the system by various impacts such as disclosing sensitive files allowing for privileged session forgery.

Proxmox proxmox-widget-toolkit before 4.0.9, as used in multiple Proxmox products, allows XSS via the edit notes feature.

An issue in Proxmox Server Solutions GmbH Proxmox VE v.5.4 thru v.8.0, Proxmox Backup Server v.1.1 thru v.3.0, and Proxmox Mail Gateway v.7.1 thru v.8.0 allows a remote authenticated attacker to escalate privileges via bypassing the two-factor authentication component.

A reflected cross-site scripting (XSS) vulnerability in Proxmox Virtual Environment prior to v7.2-3 allows remote attackers to execute arbitrary web scripts or HTML via non-existent endpoints under path /api2/html/.

Proxmox Virtual Environment (PVE) and Proxmox Mail Gateway (PMG) are vulnerable to SSRF when proxying HTTP requests between pve(pmg)proxy and pve(pmg)daemon. An attacker with an unprivileged account can craft an HTTP request to achieve SSRF and file disclosure of any files on the server. Also, in Proxmox Mail Gateway, privilege escalation to the root@pam account is possible if the backup feature has ever been used, because backup files such as pmg-backupYYYYMMDD.tgz have 0644 permissions and contain an authkey value. This is fixed in pve-http-server 4.1-3.

A response-header CRLF injection vulnerability in the Proxmox Virtual Environment (PVE) and Proxmox Mail Gateway (PMG) web interface allows a remote attacker to set cookies for a victim's browser that are longer than the server expects, causing a client-side DoS. This affects Chromium-based browsers because they allow injection of response headers with %0d. This is fixed in pve-http-server 4.1-3.

Proxmox VE prior to 3.2: 'AccessControl.pm' User Enumeration Vulnerability

Open redirect vulnerability in Proxmox Mail Gateway prior to hotfix 4.0-8-097d26a9 allows remote attackers to redirect users to arbitrary web sites and conduct phishing attacks via the destination parameter.

Multiple cross-site scripting (XSS) vulnerabilities in Proxmox Mail Gateway prior to hotfix 4.0-8-097d26a9 allow remote attackers to inject arbitrary web script or HTML via multiple parameters, related to /users/index.htm, /quarantine/spam/manage.htm, /quarantine/spam/whitelist.htm, /queues/mail/index/, /system/ssh.htm, /queues/mail/?domain=, and /quarantine/virus/manage.htm.

Multiple cross-site scripting (XSS) vulnerabilities in Proxmox Mail Gateway before 3.1-5829 allow remote attackers to inject arbitrary web script or HTML via the (1) state parameter to objects/who/index.htm or (2) User email address to quarantine/spam/manage.htm.