CVE-2018-18397 Information

Description

The userfaultfd implementation in the Linux kernel before 4.19.7 mishandles access control for certain UFFDIO_ ioctl calls as demonstrated by allowing local users to write data into holes in a tmpfs file (if the user has read-only access to that file and that file contains holes) related to fs/userfaultfd.c and mm/userfaultfd.c.

CVSS Vector

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

Reference

http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=29ec90660d68bbdd69507c1c8b4e33aa299278b1 https://access.redhat.com/errata/RHBA-2019:0327 https://access.redhat.com/errata/RHSA-2019:0163 https://access.redhat.com/errata/RHSA-2019:0202 https://access.redhat.com/errata/RHSA-2019:0324 https://access.redhat.com/errata/RHSA-2019:0831 https://bugs.chromium.org/p/project-zero/issues/detail?id=1700 https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.14.87 https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.19.7 https://github.com/torvalds/linux/commit/29ec90660d68bbdd69507c1c8b4e33aa299278b1 https://usn.ubuntu.com/3901-1/ https://usn.ubuntu.com/3901-2/ https://usn.ubuntu.com/3903-1/ https://usn.ubuntu.com/3903-2/

Attack Complexity

LOW

Privileges Required

LOW

User Interaction Required

LOW

Scope

NONE

Confidentiality Impact

UNCHANGED

Integrity Impact

NONE

Availability Impact

HIGH

Base Score

NONE

Base Severity

5.5