CVE-2020-3955 Cross-site scripting in ESXi

Critical 9.3 Published 29 Apr 2020 Updated 4 Aug 2024

An attacker can execute arbitrary scripts in the ESXi management interface by exploiting improper neutralization of HTML in VM attributes.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: A user has to click or open something
Fix: None listed

What is CVE-2020-3955?

CVE-2020-3955 is a critical cross-site scripting vulnerability in Vmware Esxi, published on 29 Apr 2020. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

Official description

ESXi 6.5 without patch ESXi650-201912104-SG and ESXi 6.7 without patch ESXi670-202004103-SG do not properly neutralize script-related HTML when viewing virtual machines attributes. VMware has evaluated the severity of this issue to be in the Important severity range with a maximum CVSSv3 base score of 8.3.

Weakness: CWE-79

Which versions are affected by CVE-2020-3955?

It affects 1 product.

Products include Vmware Esxi.

How do I fix CVE-2020-3955?

No fix has been published for CVE-2020-3955 yet. Limit exposure of the affected software until one is available.

Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.

Is CVE-2020-3955 being exploited?

There is no known exploitation of CVE-2020-3955 in the wild and no public exploit code.

All Vmware Esxi vulnerabilities

Sources

Also known as GHSA-9g8p-cxgw-6934.