CVE-2018-12633

MEDIUM

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.

References

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

Details

Source: MITRE

Published: 2018-06-22

Updated: 2018-08-21

Type: CWE-362

Risk Information

CVSS v2.0

Base Score: 6.3

Vector: AV:L/AC:M/Au:N/C:C/I:N/A:C

Impact Score: 9.2

Exploitability Score: 3.4

Severity: MEDIUM

CVSS v3.0

Base Score: 6.3

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

Impact Score: 5.2

Exploitability Score: 1

Severity: MEDIUM