CVE-2021-22017Known exploitationNetwork attack vector

Internal endpoint access via improper URI normalization

Published Sep 23, 2021 · Updated Oct 21, 2025

Improper access control in VMware vCenter Server 6.5 and 6.7 allows remote attackers to reach internal endpoints through port 443. Rhttpproxy incorrectly normalizes attacker-controlled request URIs before enforcing proxy routing restrictions, allowing crafted paths to bypass the intended boundary. Exploitation requires network access to the HTTPS service and grants access to otherwise restricted internal endpoints without authentication.

CVSS severity7.3
High
EPSS probability49.18%
Next 30 days · Sep 16, 2026
Known exploitationReported
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Improper access control in VMware vCenter Server 6.5 and 6.7 allows remote attackers to reach internal endpoints through port 443. Rhttpproxy incorrectly normalizes attacker-controlled request URIs before enforcing proxy routing restrictions, allowing crafted paths to bypass the intended boundary. Exploitation requires network access to the HTTPS service and grants access to otherwise restricted internal endpoints without authentication.

The record

CVE
CVE-2021-22017
Published
Sep 23, 2021
Updated
Oct 21, 2025
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-23, T1210
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 23, 2021CVE publishedPublication date reported by the CVE source.
  2. Oct 21, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

7.3VMwareCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsShadowserver observations through Sep 16, 2026. Gaps indicate unavailable data.
Sep 10, 2026Sep 16, 2026
View daily counts
Reporting dayUnique IPs
Sep 10, 20264
Sep 11, 2026Unavailable
Sep 12, 2026Unavailable
Sep 13, 2026Unavailable
Sep 14, 2026Unavailable
Sep 15, 2026Unavailable
Sep 16, 2026Unavailable
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationReported
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-23Relative Path Traversal
T1210Exploitation of Remote Services

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Reported exploitation

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo