A patch was pushed to the mainline Linux kernel December 2, four days after it was privately disclosed. Pettersson has developed a proof-of-concept exploit specifically for Ubuntu distributions, but told Threatpost his attack could be ported to other distros with some changes. The vulnerability is a race condition that was discovered in the af_packet implementation in the Linux kernel, and Pettersson said that a local attacker could exploit the bug to gain kernel code execution from unprivileged processes. He said the bug cannot be exploited remotely.
"Basically it's a bait-and-switch," the researcher told Threatpost. "The bug allows you to trick the kernel into thinking it is working with one kind of object, while you actually switched it to another kind of object before it could react."