Webserver POST to vROps uploadova endpoint indicative of CVE-2021-21972 exploitation

Alerts on POST requests to the uploadova endpoint tied to CVE-2021-21972 vSphere exploitation.

FreeReviewedSigma · High · v5

Category: webserver
Author: Bhabesh Raj (SigmaHQ), DRL 1.1
Published: 2021-02-24
Updated: 2026-07-31

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 targeting the /ui/vropspluginui/rest/services/uploadova endpoint, which matches behavior associated with exploitation of the VSphere remote code execution issue referenced as CVE-2021-21972. Attackers may use this upload-related interaction to trigger malicious activity against affected vROps components exposed via the web interface. Detection relies on webserver telemetry that records HTTP method and URI query path for inbound requests to the endpoint.

Reporting behind it

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Webserver POST to vROps uploadova endpoint indicative of CVE-2021-21972 exploitation

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.

webserver-post-to-ui-vropspluginui-rest-services-uploadova-indicates-cve-2021-21-179ed852

title: Webserver POST to vROps uploadova endpoint indicative of CVE-2021-21972 exploitation
id: 078d0592-95df-40c1-9557-073521143500
status: test
description: This rule flags HTTP POST requests targeting the /ui/vropspluginui/rest/services/uploadova endpoint, which matches behavior associated with exploitation of the VSphere remote code execution issue referenced as CVE-2021-21972. Attackers may use this upload-related interaction to trigger malicious activity against affected vROps components exposed via the web interface. Detection relies on webserver telemetry that records HTTP method and URI query path for inbound requests to the endpoint.
references:
  - https://www.vmware.com/security/advisories/VMSA-2021-0002.html
  - https://f5.pm/go-59627.html
  - https://swarm.ptsecurity.com/unauth-rce-vmware
  - https://github.com/SigmaHQ/sigma/blob/master/rules-emerging-threats/2021/Exploits/CVE-2021-21972/web_cve_2021_21972_vsphere_unauth_rce_exploit.yml
author: Bhabesh Raj, Huntrule Team
date: 2021-02-24
modified: 2023-01-02
tags:
  - attack.initial-access
  - attack.t1190
  - cve.2021-21972
  - detection.emerging-threats
logsource:
  category: webserver
detection:
  selection:
    cs-method: POST
    cs-uri-query: /ui/vropspluginui/rest/services/uploadova
  condition: selection
falsepositives:
  - OVA uploads to your VSphere appliance
level: high
license: DRL-1.1
related:
  - id: 179ed852-0f9b-4009-93a7-68475910fd86
    type: derived

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