CVE-2018-12633 Information

Description

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.

CVSS Vector

CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:H

Reference

http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=bd23a7269834dc7c1f93e83535d16ebc44b75eba https://bugzilla.kernel.org/show_bug.cgi?id=200131 https://github.com/torvalds/linux/commit/bd23a7269834dc7c1f93e83535d16ebc44b75eba

Attack Complexity

HIGH

Privileges Required

LOW

User Interaction Required

LOW

Scope

NONE

Confidentiality Impact

UNCHANGED

Integrity Impact

HIGH

Availability Impact

NONE

Base Score

HIGH

Base Severity

6.3