huntrule

VMware vCenter Server file upload exploitation attempt for CVE-2021-22005 via POST telemetry endpoint

Identifies POST requests targeting a vCenter telemetry upload endpoint consistent with CVE-2021-22005 exploitation attempts.

FreeReviewedSigma · High · v5
Category
webserver
Author
Sittikorn S (SigmaHQ), DRL 1.1
Published
2021-09-24
Updated
2026-07-31
AnalysisDetection

ATT&CK techniques

Initial Access

  1. Recon

  2. Resource Dev

  3. Initial Access

  4. Execution

  5. Persistence

  6. Priv Esc

  7. Defense Evasion

  8. Cred Access

  9. Discovery

  10. Lateral Movement

  11. Collection

  12. C2

  13. Exfiltration

  14. Impact

What it detects

This rule flags HTTP POST requests that contain the URI query path associated with vCenter Server analytics telemetry file upload behavior tied to CVE-2021-22005. Attackers can use this file upload weakness to gain an initial foothold by delivering malicious content through the targeted web endpoint. The detection relies on webserver telemetry capturing the HTTP method and the presence of a specific URI query substring in the request.

Reporting behind it

Related detections9 linkedT1190 — drag to rearrange
Malicious Node.js Process Spawning Unix Shell or Network Client
Malicious SharePoint ToolShell Exploitation via ToolPane Endpoint
Malicious Exchange Mailbox Export to ASPX via New-MailboxExportRequest
Suspicious Shell Spawned by ActiveMQ Java Process
Cleo Autorun Exploitation via Healthcheck File Drop
Suspicious SharePoint Worker Process Spawning Command Interpreter via ToolShell
Malicious IIS Worker Process Spawning Command Shell Reconnaissance
Potential StyleSmuggler (CVE-2026-75650) Exploitation Attempt - Magento GraphQL Styles Parameter (via webserver)
Cisco IOS XE Configuration Change by Web UI WSMA User
VMware vCenter Server file upload exploitation attempt for CVE-2021-22005 via POST telemetry endpoint
Pivot detection · T1190 · 9 related

Changelog

v5
  1. v5
    Candidate ingested via manual entry.2026-07-31
  2. v4
    Candidate ingested via manual entry.2026-07-31
  3. v3
    Candidate ingested via manual entry.2026-07-31
  4. v2
    Candidate ingested via manual entry.2026-07-31
  5. v1
    No changelog recorded for this version.2026-07-30

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.