CVE-2021-22017

Name: CVE-2021-22017
Creator: NVD / NIST
Published: 2021-09-23T13:15:08.207+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 5.3/10Actively ExploitedEPSS 46.72%

Last modified Jun 17, 2026

CVE-2021-22017 is a medium-severity vulnerability rated 5.3/10 on the CVSS scale. 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.. CISA has confirmed active exploitation in the wild. EPSS estimates a 46.72% chance of exploitation in the next 30 days.

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.

Metrics

CVSS 3.1

5.3/10

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

EPSS Probability

46.72%

98.7th percentile

Probability of exploitation in the next 30 days. Learn more

Exploitation Status

This vulnerability is listed in CISA’s Known Exploited Vulnerabilities catalog, confirming active exploitation in the wild. Federal agencies must remediate by Jan 24, 2022.

Affected Software

Vendor	Product	Versions
Vmware	Vcenter Server	6.7

References

https://www.vmware.com/security/advisories/VMSA-2021-0020.htmlPatch, Vendor Advisory
https://www.vmware.com/security/advisories/VMSA-2021-0020.htmlPatch, Vendor Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-22017US Government Resource

Timeline

Published: Sep 23, 2021
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2021-22017?

How severe is CVE-2021-22017?

CVE-2021-22017 has a CVSS score of 5.3/10 (MEDIUM severity). The EPSS model estimates a 46.72% probability of exploitation in the next 30 days. This vulnerability is listed in CISA's Known Exploited Vulnerabilities catalog.

How do I fix CVE-2021-22017?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-22017?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST