VMware ESXi 5.5 Update 1 Driver Rollup 2 Released Apr 24 2014
Official access to the ESXi 5.5 ISO is now highly restricted following Broadcom's acquisition of VMware. vmware esxi 5.5 iso download
ESXi 5.5 is a legacy Type 1 hypervisor that was a major milestone for VMware, though it is now considered VMware ESXi 5
Alternate official link (still redirects to login): CVE-2021-21972 – vCenter Server RCE (affects vCenter 5
Why caution? Malicious actors inject rootkits or backdoors into old hypervisor ISOs. Never run an unchecked legacy ISO in a production environment.