How severe is CVE-2021-21973?

CVE-2021-21973 has a CVSS 3.1 base score of 5.3 (MEDIUM). EPSS estimates a 87.6% probability of exploitation in the next 30 days. It is listed in the CISA Known Exploited Vulnerabilities catalog.

CVE-2021-21973: VMware vCenter Server and Cloud Foundation Server

CISA Known Exploited Vulnerabilities

VMware vCenter Server and Cloud Foundation Server Side Request Forgery (SSRF) Vulnerability is confirmed as actively exploited and is listed in the CISA KEV catalog.

Added to KEV

2022-03-07

Remediation due

2022-03-21

Required action
Apply updates per vendor instructions.

CISA notes
https://nvd.nist.gov/vuln/detail/CVE-2021-21973

Description

The vSphere Client (HTML5) contains an SSRF (Server Side Request Forgery) vulnerability due to improper validation of URLs in a vCenter Server plugin. A malicious actor with network access to port 443 may exploit this issue by sending a POST request to vCenter Server plugin leading to information disclosure. This affects: VMware vCenter Server (7.x before 7.0 U1c, 6.7 before 6.7 U3l and 6.5 before 6.5 U3n) and VMware Cloud Foundation (4.x before 4.2 and 3.x before 3.10.1.2).

Severity

CVSS 3.1 · CISA5.3 MEDIUM

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

SSVC · CISA-ADP

Exploitationactive

Automatableyes

Technical impactpartial

Affected Products

Vendor	Product	Affected versions
-	VMware vCenter Server	7.x before 7.0 U1c 6.7 before 6.7 U3l 6.5 before 6.5 U3n
-	VMware Cloud Foundation	4.x before 4.2 3.x before 3.10.1.2

References

1 Links

Other references

https://www.vmware.com/security/advisories/VMSA-2021-0002.html

Record Details

Published

2021-02-24

Last updated

2025-10-21

Assigner (CNA)

vmware

Credited to

CVE record data © The MITRE Corporation, used under the CVE Terms of Use. Exploited-in-the-wild data from the CISA Known Exploited Vulnerabilities catalog (CC0). Exploit prediction scores by FIRST EPSS (first.org/epss). This site is not endorsed or certified by MITRE, NVD, CISA, or FIRST.