Is CVE-2021-22017 in the CISA KEV catalog?

Yes. CVE-2021-22017 is on the CISA Known Exploited Vulnerabilities list, added 2022-01-10.

What is the CVSS severity of CVE-2021-22017?

CVE-2021-22017 has a CVSS v3 base score of 5.3 (MEDIUM).

What is the EPSS score for CVE-2021-22017?

CVE-2021-22017 has an EPSS score of 46.72% (99th percentile), estimating the probability of exploitation in the next 30 days.

CVE & CISA-KEV Catalog

CVE-2021-22017

MEDIUMCISA KEVEPSS 99th pctl

5.3

CVSS v3

NVD

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.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityLow

IntegrityNone

AvailabilityNone

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

Exploit Intelligence

46.72%probability of exploitation in 30 days

99thpercentile

Very high risk: more likely to be exploited than 99% of all known CVEs.

Known Exploited Vulnerability (CISA KEV)

VMware vCenter Server Improper Access Control

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

Apply updates per vendor instructions.

Remediation due: 2022-01-24

References

Find and fix vulnerabilities across your fleet

TridentStack Control continuously scans your Windows, macOS, and Linux fleet for known vulnerabilities, prioritizes them by severity and active exploitation, and patches them automatically.

Start free

This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2025-10-30.