VMware has confirmed the leak of source code from its ESX hypervisor, warning possibly more files could be revealed in the future.

Details of the leak were first reported by CRN, noting that a hacker affiliated with LulzSec posted the source code on Pastebin.
VMware said that the code dates back to 2003 and 2004, before its newer ESXi hypervisor was released, Ars Technica reported.
While it’s probably not good news for companies that use ESX, VMware said the leak “does not necessarily mean that there is any increased risk to VMware customers.”
“VMware proactively shares its source code and interfaces with other industry participants to enable the broad virtualisation ecosystem today,” it said.
Its Security Response Center has been engaged to thoroughly investigate the leak and will provide updates to the VMware community “if and when” additional information is available.
One large VMware ESX Australian customer is retail giant Coles, which ran the hypervisor at its headquarters despite a wider virtualisation project based on Microsoft’s Hyper-V virtaualisation platform. Health insurance company HBF is also a known user.
Kaspersky blog Threat Post claims the leaked documents are tied to attacks on CEIEC, the China Electronics Import & Export Corporation in March.
The breach does not appear to be as serious as that recently faced by Symantec, which lost source code to its pcAnywhere remote acccess software and to components of old versions of Norton.