Vulnerabilities affect vCenter Server 6.5, 6.7, and 7.0, and vSphere Cloud Foundation (vCenter Server) 3.x and 4.x. The vulnerabilities can be exploited by a malicious actor with network access to port 443. There is currently no proof-of-concept code available for either of the flaws. Researchers have used the Shodan search engine to discover how many still vulnerable VMWare vCenter server instances are currently connected to the internet.
Source: https://www.helpnetsecurity.com/2021/05/26/cve-2021-21985/