ESXi vulnerablities are in the news recently as they are being exploited en masse… not that active news coverage should be the sole driver for patching a server. The SLP (Service Location Protocol) service runs as root and parses network input without authentication. Since 2021 the recommendation from VMWare has been to disable the service. Newer versions (ie. 7.0 U2c and 8.0) disable it by default.

VMWare has an article - How to Disable/Enable the SLP Service on VMware ESXi (76372) - describing how to disable the service.

Essentially, enable SSH on the host server, then connect to it with pUTTY or a similar tool. Stop the SLD service: /etc/init.d/slpd stop Disable the SLP service: esxcli network firewall ruleset set -r CIMSLP -e 0 Make the change persistent across reboots: chkconfig slpd off Confirm the change is persistent: chkconfig --list | grep slpd

The server does not need a reboot for this change to take effect.