Hypervisor Security Testing

Proxmox VE Security Testing: API Tokens, Web Console, Cluster Management, and VM Access

📅 July 3, 2026 ⏱ 14 min read 🏷 Proxmox VE, Hypervisor Security, API Token Exposure, VNC Console Access, Cluster Privilege Escalation

Proxmox VE is the most widely deployed open-source hypervisor for self-hosted virtualization, running the underlying infrastructure for all VMs and LXC containers in a home lab or small datacenter. Its security impact is fundamentally different from application-layer tools: Proxmox runs as root and all API operations execute with root-level host privileges, meaning a compromised Proxmox API token gives an attacker root on the bare metal and control over every VM and container on the host. Key security assessment areas include: API tokens created in Datacenter > Permissions > API Tokens are long-lived and stored in /etc/pve/user.cfg; the vncproxy and termproxy endpoints provide interactive console access to any VM; cluster nodes share the /etc/pve distributed filesystem giving each node full visibility into all API tokens and user configurations; and Proxmox's default self-signed certificate often causes users to disable certificate verification in automation scripts, enabling MITM. This guide covers systematic Proxmox VE security assessment.

Authentication and API Token Testing
VM and Container Enumeration
Web Console Access
Proxmox Security Hardening

Authentication and API Token Testing

# Proxmox VE REST API — authentication via ticket or API token
PROXMOX_URL="https://proxmox.example.com:8006"

# Authenticate with username/password to get a ticket and CSRF token
AUTH_RESPONSE=$(curl -sk -X POST "${PROXMOX_URL}/api2/json/access/ticket" \
  -d "username=root@pam&password=yourpassword" 2>/dev/null)
echo "$AUTH_RESPONSE" | python3 -c "
import json,sys
d=json.load(sys.stdin)
data = d.get('data',{})
print(f'Ticket: {data.get(\"ticket\",\"FAILED\")[:40]}...')
print(f'CSRF token: {data.get(\"CSRFPreventionToken\",\"FAILED\")}')
print(f'Username: {data.get(\"username\")}')
" 2>/dev/null

TICKET=$(echo "$AUTH_RESPONSE" | python3 -c "import json,sys; print(json.load(sys.stdin)['data']['ticket'])" 2>/dev/null)
CSRF=$(echo "$AUTH_RESPONSE" | python3 -c "import json,sys; print(json.load(sys.stdin)['data']['CSRFPreventionToken'])" 2>/dev/null)

# Test API token authentication (format: USER@REALM!TOKENID=SECRET)
# API tokens are created in Datacenter > Permissions > API Tokens
API_TOKEN="root@pam!mytoken=xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
curl -sk -H "Authorization: PVEAPIToken=${API_TOKEN}" \
  "${PROXMOX_URL}/api2/json/nodes" 2>/dev/null | python3 -c "
import json,sys
d=json.load(sys.stdin)
nodes = d.get('data',[])
print(f'Cluster nodes: {len(nodes)}')
for n in nodes:
    print(f'  {n.get(\"node\")} status={n.get(\"status\")} cpu={n.get(\"cpu\"):.2f} mem={n.get(\"mem\")}')
" 2>/dev/null

# List all users and API tokens (requires Datacenter.Audit permission)
curl -sk -b "PVEAuthCookie=${TICKET}" -H "CSRFPreventionToken: ${CSRF}" \
  "${PROXMOX_URL}/api2/json/access/users?full=1" 2>/dev/null | python3 -c "
import json,sys
d=json.load(sys.stdin)
users = d.get('data',[])
print(f'Users: {len(users)}')
for u in users:
    print(f'  {u.get(\"userid\")} enable={u.get(\"enable\")} tokens={len(u.get(\"tokens\",{}))}')
    for tok_id, tok in u.get('tokens',{}).items():
        print(f'    Token: {tok_id} expire={tok.get(\"expire\",\"never\")}')
" 2>/dev/null

VM and Container Enumeration

# Proxmox VM and LXC enumeration — full inventory with resource allocation
PROXMOX_URL="https://proxmox.example.com:8006"
TICKET="your-pve-auth-cookie"
CSRF="your-csrf-token"
NODE="pve"

# Enumerate all VMs on a node
curl -sk -b "PVEAuthCookie=${TICKET}" -H "CSRFPreventionToken: ${CSRF}" \
  "${PROXMOX_URL}/api2/json/nodes/${NODE}/qemu" 2>/dev/null | python3 -c "
import json,sys
d=json.load(sys.stdin)
vms = d.get('data',[])
print(f'VMs on node {\"$NODE\"}: {len(vms)}')
for vm in sorted(vms, key=lambda x: x.get('vmid',0)):
    print(f'  VM {vm.get(\"vmid\")}: {vm.get(\"name\",\"unnamed\")} status={vm.get(\"status\")} mem={vm.get(\"mem\",0)//1024//1024}GB')
" 2>/dev/null

# Enumerate all LXC containers
curl -sk -b "PVEAuthCookie=${TICKET}" -H "CSRFPreventionToken: ${CSRF}" \
  "${PROXMOX_URL}/api2/json/nodes/${NODE}/lxc" 2>/dev/null | python3 -c "
import json,sys
d=json.load(sys.stdin)
ctrs = d.get('data',[])
print(f'LXC containers on node: {len(ctrs)}')
for c in sorted(ctrs, key=lambda x: x.get('vmid',0)):
    print(f'  CT {c.get(\"vmid\")}: {c.get(\"name\",\"unnamed\")} status={c.get(\"status\")}')
" 2>/dev/null

# Get VM configuration — reveals disks, network interfaces, boot order
VMID=100
curl -sk -b "PVEAuthCookie=${TICKET}" -H "CSRFPreventionToken: ${CSRF}" \
  "${PROXMOX_URL}/api2/json/nodes/${NODE}/qemu/${VMID}/config" 2>/dev/null | python3 -c "
import json,sys
d=json.load(sys.stdin)
cfg = d.get('data',{})
print(f'VM config:')
print(f'  Memory: {cfg.get(\"memory\")}MB')
print(f'  CPUs: {cfg.get(\"cores\")}')
for key, val in cfg.items():
    if key.startswith('net'):
        print(f'  {key}: {val}')
    if key.startswith('scsi') or key.startswith('virtio') or key.startswith('ide'):
        print(f'  Disk {key}: {val}')
" 2>/dev/null

Web Console Access

# Proxmox VNC/SPICE console — interactive access to any VM
PROXMOX_URL="https://proxmox.example.com:8006"
TICKET="your-pve-auth-cookie"
CSRF="your-csrf-token"
NODE="pve"
VMID=100

# Request a VNC proxy ticket for a VM — this opens a noVNC web console
VNC_RESPONSE=$(curl -sk -X POST \
  -b "PVEAuthCookie=${TICKET}" \
  -H "CSRFPreventionToken: ${CSRF}" \
  "${PROXMOX_URL}/api2/json/nodes/${NODE}/qemu/${VMID}/vncproxy" \
  -d "websocket=1&generate-password=1" 2>/dev/null)
echo "$VNC_RESPONSE" | python3 -c "
import json,sys
d=json.load(sys.stdin)
data = d.get('data',{})
print(f'VNC ticket: {data.get(\"ticket\",\"FAILED\")}')
print(f'VNC port: {data.get(\"port\")}')
print(f'VNC password: {data.get(\"passwd\")}')
# This ticket can be used to open a WebSocket VNC connection to the VM
" 2>/dev/null

# Request terminal proxy for LXC container (shell access)
CTID=101
curl -sk -X POST \
  -b "PVEAuthCookie=${TICKET}" \
  -H "CSRFPreventionToken: ${CSRF}" \
  "${PROXMOX_URL}/api2/json/nodes/${NODE}/lxc/${CTID}/termproxy" 2>/dev/null | python3 -c "
import json,sys
d=json.load(sys.stdin)
data = d.get('data',{})
print(f'Term ticket: {data.get(\"ticket\",\"FAILED\")}')
print(f'Term port: {data.get(\"port\")}')
" 2>/dev/null

Proxmox VE Security Hardening

Proxmox VE Security Hardening Checklist:

Create dedicated API tokens with least-privilege roles instead of using root@pam — Proxmox API tokens support privilege separation; create tokens with only the permissions needed for each use case (e.g., VM.Monitor for monitoring, Datastore.AllocateSpace for backup); the token secret is only shown once at creation and must be stored securely; tokens in /etc/pve/user.cfg are readable by all cluster nodes
Change the default root@pam password immediately and enable two-factor authentication — the root password used during Proxmox installation is the same root password on the underlying Debian host; enable TOTP or WebAuthn for the root@pam account in Datacenter > Permissions > Two Factor; note that API tokens bypass 2FA by design — this is expected behavior
Restrict Proxmox web UI access to trusted networks — the Proxmox web interface on port 8006 should not be internet-accessible; place it behind a VPN or restrict access with firewall rules; the web UI provides complete control over all VMs and containers including console access and configuration changes
Replace the self-signed certificate — Proxmox's default self-signed certificate causes users to disable TLS verification in automation scripts; use the built-in ACME/Let's Encrypt integration (Datacenter > ACME) to get a valid certificate; valid certificates prevent MITM attacks against Proxmox API automation
Audit cluster node trust — in a Proxmox cluster, all nodes share /etc/pve via the corosync distributed filesystem; a compromised cluster node has access to all API tokens, user configurations, and SSL certificates for all nodes in the cluster; treat cluster node compromise as equivalent to cluster-wide compromise
Use Proxmox firewall rules for VM network isolation — enable the Proxmox firewall at datacenter, node, and VM levels; configure security groups to prevent VMs from communicating with the Proxmox management interface (port 8006) to prevent VM-to-host breakout via the API; the management interface should only be reachable from the administrative VLAN

Security Test	Method	Risk
API token with root-equivalent permissions	POST /api2/json/access/ticket with root@pam credentials — ticket gives full cluster control; API tokens created with Datacenter Administrator role have equivalent access and are long-lived; list tokens via GET /api2/json/access/users?full=1	Critical
VM console access via vncproxy	POST /nodes/{node}/qemu/{vmid}/vncproxy — returns a VNC ticket that opens an interactive console to the VM; equivalent to physical keyboard/monitor access; no separate VM-level authentication required	Critical
LXC container shell access via termproxy	POST /nodes/{node}/lxc/{ctid}/termproxy — returns a terminal proxy ticket for direct shell access to the LXC container; equivalent to running lxc-attach on the host	Critical
Cluster node credential sharing	Read /etc/pve/user.cfg on any cluster node — contains all API token IDs, hashed passwords, and permission assignments for the entire cluster; compromise of one cluster node exposes credentials for all nodes	Critical
ACME/Let's Encrypt credential exposure	GET /api2/json/cluster/acme/plugins — returns configured ACME DNS plugin credentials (Cloudflare API tokens, Route53 keys, etc.) used for certificate issuance; DNS provider credentials stored in plaintext	High

Automate Proxmox VE Security Testing

Ironimo tests Proxmox VE deployments for API token enumeration and privilege assessment, default root@pam credential validation, VM and LXC console access via vncproxy and termproxy, cluster node credential sharing in /etc/pve/user.cfg, ACME DNS plugin credential exposure, firewall configuration review, and TLS certificate validation.

Start free scan

Table of Contents

Authentication and API Token Testing

VM and Container Enumeration

Web Console Access

Proxmox VE Security Hardening

Automate Proxmox VE Security Testing