CVE-2013-1661: VMware ESXi 4.0 through 5.1, and ESX 4.0 and 4.1, does not properly implement the Network File Copy (NFC) p...

Security readout for executives and security teams

This is a denial-of-service issue in older VMware ESX/ESXi platforms. A network attacker positioned between NFC client and server traffic could alter the stream and trigger an unhandled exception and crash. The provided sources do not show data theft, code execution, or confirmed active exploitation. Exposure is limited to environments still running the listed legacy VMware ESXi or ESX versions. Risk is higher where NFC-related management or file-copy traffic can be intercepted or altered between client and server. Products and versions outside the cited range are not established by the provided sources. Medium priority unless affected legacy VMware hosts remain in production. The issue can disrupt virtualization operations, but supplied evidence shows denial of service only and no confirmed active exploitation. Prioritize discovery first, then remediate any matching hosts using VMware guidance. Mitigation focus: Check VMware VMSA-2013-0011 for vendor-confirmed fixes or workarounds.; Inventory and prioritize affected ESXi 4.0-5.1 and ESX 4.0/4.1 systems.; Restrict management and NFC-related traffic to trusted administrative networks..

Prepared

Jun 14, 2026, 15:32 UTC (UTC+00:00)

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.