An issue was discovered in secdrv.sys as shipped in Microsoft Windows Vista, Windows 7, Windows 8, and Windows 8.1 before KB3086255, and as shipped in Macrovision SafeDisc. Two carefully timed calls to IOCTL 0xCA002813 can cause a race condition that leads to a use-after-free. When exploited, an unprivileged attacker can run arbitrary code in the kernel.