CVE-2021-21991

high-risk
Published 2021-09-22

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).

Do I need to act?

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0.19% chance of exploitation
EPSS score — low exploit probability
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Not on CISA KEV list
No confirmed active exploitation reported to CISA
?
Patch status unknown
Check vendor advisories for fix availability and mitigation guidance
7
CVSS 7.8/10 High
LOCAL / LOW complexity

Affected Vendors

51
/ 100
high-risk
Severity 24/34 · High
Exploitability 1/34 · Minimal
Exposure 26/34 · High