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CVE-2021-22017

5.3, medium Known exploited

VMware vCenter Server Improper Access Control

NVD (opens in a new tab) CVE.org (opens in a new tab) CISA KEV catalogue (opens in a new tab)
CVSS
5.3, medium medium CVSS v3.1
EPSS, next 30 days
49% higher than 98.8% of scored CVEs
Exploitation
Confirmed in the wild
Published
23 Sept 20215 years ago

Known exploited

CISA added this to the Known Exploited Vulnerabilities Catalog on 10 Jan 2022. US federal agencies had to remediate by 24 Jan 2022, a deadline that has passed.

Required action. Apply updates per vendor instructions.

Description

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.

Details

Vendor
VMware
Product
VMware vCenter Server, VMware Cloud Foundation
Weakness
n/a
Status
Analyzed
Updated
17 Jun 2026
Assigner
security@vmware.com

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

References 2

Patches and fixes 1

Other references 1

The kind is read from NVD's tags where present and from the shape of the URL otherwise, so treat it as a hint.

Other VMware CVEs

Every VMware CVE we hold

Same vendor in what we hold, not a known link between the flaws.

  • CVE-2025-22224 VMware ESXi and Workstation TOCTOU Race Condition Vulnerability KEV EPSS 2% 8.2, high
  • CVE-2025-22225 VMware ESXi Arbitrary Write Vulnerability KEV EPSS 1% 8.2, high
  • CVE-2025-22226 VMware ESXi, Workstation, and Fusion Information Disclosure Vulnerability KEV EPSS 2% 6, medium
  • CVE-2024-38812 VMware vCenter Server Heap-Based Buffer Overflow Vulnerability KEV EPSS 55% 9.8, critical
  • CVE-2024-38813 VMware vCenter Server Privilege Escalation Vulnerability KEV EPSS 17% 9.8, critical
  • CVE-2024-37085 VMware ESXi Authentication Bypass Vulnerability KEV EPSS 27% 7.2, high
  • CVE-2023-34048 VMware vCenter Server Out-of-Bounds Write Vulnerability KEV EPSS 99% 9.8, critical
  • CVE-2023-20867 VMware Tools Authentication Bypass Vulnerability KEV EPSS 14% 3.9, low

Beyond this page

Is CVE-2021-22017 in your network?

This page tells you how dangerous CVE-2021-22017 is out there. Whether it sits on one of your devices, only a scan of your own network can tell. That is what our systems do, every day, for the companies we protect.

CVE-2021-22017 is in the CISA catalogue of exploited vulnerabilities: attackers are already exploiting it.

  • EXYS7600 OCELOT

    Find it before attackers do

    Ocelot scans your network on a schedule and reports every vulnerability it finds by its CVE identifier, with its CVSS score and how many of your hosts are affected. A finding like CVE-2021-22017 comes with the devices to patch.

    Learn more about EXYS7600 OCELOT

  • EXYS7950 KONDRA

    Detect it if it's exploited

    Until the patch is applied, Kondra monitors your network, events and endpoints in real time. It keeps an inventory of the software installed on every endpoint, and its anomaly detection rules flag what an attacker does once inside.

    Learn more about EXYS7950 KONDRA
Check your exposure

Assembled from the NVD 2.0 API, the CISA Known Exploited Vulnerabilities Catalog and FIRST EPSS. Scores are as of our last collection on 17 Oct 2026, not the live upstream state.