IRONSMITHINTEL
MEDIUMCVSS5.3
|
Actively Exploited
|CISA KEV|CVE-2021-22017|Auth: none — unauthenticated|Reboot: required|Manual only

VMware vCenter Server Improper Access Control

Rhttproxy as used in vCenter Server contains a vulnerability due to improper implementation of URI normalization.

Published Sep 23, 2021 · Updated May 16, 2026
Why patchRisk explained in plain English
Worst-case scenarioIf unpatched

A remote attacker, without authentication, can achieve partial data exposure. Federal agencies are required to remediate by 2022-01-24 under CISA BOD 22-01.

How the attack worksNo clicks needed

This vulnerability affects VMware vCenter Server. 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. Exploitation requires remote network access, low attack complexity, no authentication required, and no user interaction required.

📧

Phishing link

🖼

Malicious file

🔓

Server compromised

Am I affected?Quick check

Probably yes if any of these apply:

Virtualisation Administrators
Infrastructure Team
IT Security
Running vcenter server: 6.7
Real-world incidentsWhat we've seen

CISA added this CVE to the Known Exploited Vulnerabilities catalog on 2022-01-10 based on evidence of active exploitation in the wild. Federal agencies required to remediate by 2022-01-24.

How to patch

Manual remediation steps

Apply the Vendor Patch

This vulnerability is in the CISA Known Exploited Vulnerabilities catalog — apply the vendor's security update as soon as possible.

CISA required action: Apply updates per vendor instructions.

References

    1
    Vendor advisory: https://www.vmware.com/security/advisories/VMSA-2021-0020.html
    1
    NVD entry: https://nvd.nist.gov/vuln/detail/CVE-2021-22017
    1
    CISA KEV: https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-22017
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