CVE-2021-21973

5.3 MEDIUM CISA KEV - Actively Exploited
Published: February 24, 2021 Modified: October 30, 2025

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).

AI Explanation

Get an AI-powered plain-language explanation of this vulnerability and remediation steps.

Login to generate AI explanation

CVSS v3.x Details

0.0 Low Medium High Critical 10.0
Vector String
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory
https://www.vmware.com/security/advisories/VMSA-2021-0002.html
Source: security@vmware.com
Vendor Advisory
https://www.vmware.com/security/advisories/VMSA-2021-0002.html
Source: af854a3a-2127-422b-91ae-364da2661108
Vendor Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-21973
Source: 134c704f-9b21-4f2e-91b3-4a467353bcc0
US Government Resource

3 reference(s) from NVD

Quick Stats

CVSS v3 Score
5.3 / 10.0
EPSS (Exploit Probability)
90.3%
100th percentile
Exploitation Status
Actively Exploited
Remediation due: 2022-03-21

Weaknesses (CWE)

Affected Vendors

vmware