{"id":"CVE-2018-12633","details":"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.","modified":"2026-03-14T14:32:13.649480Z","published":"2018-06-22T00:29:00.270Z","references":[{"type":"REPORT","url":"https://bugzilla.kernel.org/show_bug.cgi?id=200131"},{"type":"FIX","url":"http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=bd23a7269834dc7c1f93e83535d16ebc44b75eba"},{"type":"FIX","url":"https://github.com/torvalds/linux/commit/bd23a7269834dc7c1f93e83535d16ebc44b75eba"}],"affected":[{"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2018-12633.json","unresolved_ranges":[{"events":[{"introduced":"0"},{"last_affected":"4.17.2"}]}]}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:H"}]}