5.3

CVE-2021-22017: VMware vCenter Server Improper Access Control

CVSS: 5.3v3.1MediumKEVAnalyzed
Published 23-09-2021Last modified 21-10-2025
Open JSON

Vulnerability summary

CVE-2021-22017 is a medium (CVSS 5.3) vulnerability in VMware vCenter Server. It is known to be exploited: CISA lists it, first on 10-01-2022. EPSS estimates a 49.18% chance of exploitation in the next 30 days, higher than 98.8% of scored vulnerabilities.

Overall risk
85/100
0100
Critical · default modelHow is this calculated?
CVSS score
5.3/10
010
Medium · v3.1 (CVE.org)
EPSS score
49.18%
0%100%
High · 0.00 pp in 30 days
KEVListedCISA
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 23-09-2021
    PublishedVulnerability first disclosed.
  2. 10-01-2022
    Added to CISA KEVVMware vCenter Server Improper Access Control
  3. 24-01-2022
    CISA remediation dueApply updates per vendor instructions.
  4. 21-10-2025
    Last modifiedVulnerability information updated.

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 metrics

3 scores · 2 sources · 2 versions

EPSS trend

Probability

49.18%

Chance of exploitation in the next 30 days

Percentile

99%

Versus all other CVEs

30-day change

0.00 pp

From 49.18% on 19-09-2026

19-09-202619-10-2026
EPSS score
49.18%

Known exploited

Compare KEV catalogs
CISA KEVListed
Added
10-01-2022
Federal due date
24-01-2022

CISA required action

Apply updates per vendor instructions. nvd.nist.gov/vuln/detail/CVE-2021-22017

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

No weakness data has been published for this record.

Affected systems

Vmware1 product

1 vendor · 1 product

References

2 links