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.

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-backup_YYYY_MM_DD_*.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.

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.