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

Analysis Detection

ATT&CK techniques

Initial Access

Recon
Resource Dev
Initial Access
- T1190Exploit Public-Facing Application
Execution
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
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
Candidate ingested via manual entry.2026-07-31
v4
Candidate ingested via manual entry.2026-07-31
v3
Candidate ingested via manual entry.2026-07-31
v2
Candidate ingested via manual entry.2026-07-31
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.

vmware-vcenter-server-file-upload-exploitation-attempt-cve-2021-22005-via-web-po-b014ea07

title: VMware vCenter Server file upload exploitation attempt for CVE-2021-22005 via POST telemetry endpoint
id: e1b97df2-1c82-4b44-89c3-fa8189f60e5d
status: test
description: 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.
references:
  - https://kb.vmware.com/s/article/85717
  - https://www.tenable.com/blog/cve-2021-22005-critical-file-upload-vulnerability-in-vmware-vcenter-server
  - https://github.com/SigmaHQ/sigma/blob/master/rules-emerging-threats/2021/Exploits/CVE-2021-22005/web_cve_2021_22005_vmware_file_upload.yml
author: Sittikorn S, Huntrule Team
date: 2021-09-24
modified: 2023-01-02
tags:
  - attack.initial-access
  - attack.t1190
  - cve.2021-22005
  - detection.emerging-threats
logsource:
  category: webserver
detection:
  selection:
    cs-method: POST
    cs-uri-query|contains: /analytics/telemetry/ph/api/hyper/send?
  condition: selection
falsepositives:
  - Vulnerability Scanning
level: high
license: DRL-1.1
related:
  - id: b014ea07-8ea0-4859-b517-50a4e5b7ecec
    type: derived

Convert

This rule as a query you can run. Uses no unlock credit.

SplunkSPL