CVE-2021-21973 VMware vCenter Server and Cloud Foundation Server Side Request Forgery (SSRF)

Exploited in the wild Medium 5.3 Published 24 Feb 2021 Updated 21 Oct 2025

A malicious actor with network access can exploit an SSRF vulnerability in the vSphere Client to disclose sensitive information from the vCenter Server.

Exploited in the wild: Since 7 Mar 2022
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2021-21973?

CVE-2021-21973 is a medium-severity server-side request forgery vulnerability in Vmware Cloud Foundation, published on 24 Feb 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official 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).

Weakness: CWE-918

Which versions are affected by CVE-2021-21973?

It affects 2 products.

Products include Vmware Cloud Foundation, Vmware Vcenter Server.

How do I fix CVE-2021-21973?

No fix has been published for CVE-2021-21973 yet. Limit exposure of the affected software until one is available. US federal agencies must fix it by 21 Mar 2022.

Upgrade, and send outbound requests through an allow-list that blocks internal addresses. More about Server-side request forgery.

Is CVE-2021-21973 being exploited?

Yes. Attackers have exploited CVE-2021-21973 in the wild since at least 7 Mar 2022.

Public exploit code: 1 Nuclei template and 1 proofs of concept on GitHub.

All Vmware Cloud Foundation vulnerabilities

Sources

Also known as GHSA-5j6h-79mj-qfq2.