### [CVE-2021-21991](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-21991)
![](https://img.shields.io/static/v1?label=Product&message=VMware%20vCenter%20Server%2C%20VMware%20Cloud%20Foundation&color=blue)
![](https://img.shields.io/static/v1?label=Version&message=VMware%20vCenter%20Server(7.x%20before%207.0%20U2c%2C%206.7%20before%206.7%20U3o%20and%206.5%20before%206.5%20U3q)%20and%20VMware%20Cloud%20Foundation%20(4.x%20before%204.3%20and%203.x%20before%203.10.2.2)%20&color=brightgreen)
![](https://img.shields.io/static/v1?label=Vulnerability&message=Local%20privilege%20escalation%20vulnerability&color=brightgreen)

### Description

The vCenter Server contains a local privilege escalation vulnerability due to the way it handles session tokens. A malicious actor with non-administrative user access on vCenter Server host may exploit this issue to escalate privileges to Administrator on the vSphere Client (HTML5) or vCenter Server vSphere Web Client (FLEX/Flash).

### POC

#### Reference
- https://www.vmware.com/security/advisories/VMSA-2021-0020.html

#### Github
- https://github.com/HynekPetrak/HynekPetrak