cpe:/o:linux:linux_kernel:4.17.2 CVE-2018-12633 2018-06-21T20:29:00.270-04:00 2018-08-21T11:42:37.667-04:00 6.3 LOCAL MEDIUM NONE COMPLETE NONE COMPLETE http://nvd.nist.gov 2018-08-14T08:55:08.887-04:00 MISC http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=bd23a7269834dc7c1f93e83535d16ebc44b75eba MISC https://bugzilla.kernel.org/show_bug.cgi?id=200131 MISC https://github.com/torvalds/linux/commit/bd23a7269834dc7c1f93e83535d16ebc44b75eba An issue was discovered in the Linux kernel through 4.17.2. vbg_misc_device_ioctl() in drivers/virt/vboxguest/vboxguest_linux.c reads the same user data twice with copy_from_user. The header part of the user data is double-fetched, and a malicious user thread can tamper with the critical variables (hdr.size_in and hdr.size_out) in the header between the two fetches because of a race condition, leading to severe kernel errors, such as buffer over-accesses. This bug can cause a local denial of service and information leakage.