---
id: "CVE-2021-22017"
kind: "vulnerability"
aliases: ["CVE-2021-22017"]
title: "VMware vCenter Server: VMware vCenter Server Improper Access Control"
severity: "high"
cvss: 5.3
epss: 0.49177
exploited: true
status: "open"
category: "infrastructure"
products: [{"name": "VMware vCenter Server", "fixed": [], "affected": "", "ecosystem": "vendor"}]
ecosystems: ["vendor"]
tags: ["exploited", "infrastructure", "self-hosted", "vcenter", "vmware"]
not_affected_if: ["default-config"]
published_at: "2021-09-23T13:15:08+00:00"
first_seen_at: "2026-10-23T19:11:53+00:00"
updated_at: "2026-10-23T21:57:35+00:00"
sources: [{"source": "kev", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2021-22017", "first_seen_at": "2026-10-23T19:11:53+00:00"}, {"source": "epss", "url": "https://api.first.org/data/v1/epss?cve=CVE-2021-22017", "first_seen_at": "2026-10-23T19:13:44+00:00"}, {"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2021-22017", "first_seen_at": "2026-10-23T21:57:35+00:00"}]
---

# VMware vCenter Server: VMware vCenter Server Improper Access Control

VMware vCenter Server's rhttproxy component mishandles URI normalization, which lets a remote request reach endpoints it should not. CISA lists it as actively exploited, so attackers can reach vCenter management functions without the access they should need.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- vendor:VMware vCenter Server affected ? fixed ?

## How to check

Check the installed vCenter version in the VAMI web interface or with 'vpxd -v' on the appliance and compare it to the patched release in the VMware advisory.

## Fix

Apply the VMware vCenter update that addresses CVE-2021-22017, per vendor instructions as CISA requires.

## Timeline

- 2026-10-23T19:11:53+00:00 kev https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2021-22017
- 2026-10-23T19:13:44+00:00 epss https://api.first.org/data/v1/epss?cve=CVE-2021-22017
- 2026-10-23T21:57:35+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2021-22017

## From the sources

Rhttproxy as used in vCenter Server contains a vulnerability due to improper implementation of URI normalization. A malicious actor with network access to port 443 on vCenter Server may exploit this issue to bypass proxy leading to internal endpoints being accessed.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_