Almost all major OS vendors released security patches yesterday after a researcher discovered that some OS makers have misinterpreted an Intel CPU debug feature and left their systems open to attacks. From a report: The vulnerability is in how the OS vendors implemented a hardware debug mechanism for Intel x86-64 architectures -- and more specifically the MOV SS and POP SS instructions. "In certain circumstances after the use of certain Intel x86-64 architecture instructions, a debug exception pointing to data in a lower ring (for most operating systems, the kernel Ring 0 level) is made available to operating system components running in Ring 3," the CERT/CC team explained in an advisory published yesterday. Explained in layman's terms, "this may allow an attacker to utilize operating system APIs to gain access to sensitive memory information or control low-level operating system functions." Operating systems that mishandle this debug exception and had their systems open to attacks include Apple, Microsoft, FreeBSD, Red Hat, Ubuntu, SUSE Linux, and other Linux distros based on the Linux Kernel -- which is also affected.