CVE-2017-18344 Information

Description

The timer_create syscall implementation in kernel/time/posix-timers.c in the Linux kernel before 4.14.8 doesn’t properly validate the sigevent-sigev_notify field which leads to out-of-bounds access in the show_timer function (called when /proc/$PID/timers is read). This allows userspace applications to read arbitrary kernel memory (on a kernel built with CONFIG_POSIX_TIMERS and CONFIG_CHECKPOINT_RESTORE).

CVSS Vector

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

Reference

http://www.securityfocus.com/bid/104909 http://www.securitytracker.com/id/1041414 https://access.redhat.com/errata/RHSA-2018:2948 https://access.redhat.com/errata/RHSA-2018:3083 https://access.redhat.com/errata/RHSA-2018:3096 https://access.redhat.com/errata/RHSA-2018:3459 https://access.redhat.com/errata/RHSA-2018:3540 https://access.redhat.com/errata/RHSA-2018:3586 https://access.redhat.com/errata/RHSA-2018:3590 https://access.redhat.com/errata/RHSA-2018:3591 https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.14.8 https://github.com/torvalds/linux/commit/cef31d9af908243421258f1df35a4a644604efbe https://usn.ubuntu.com/3742-1/ https://usn.ubuntu.com/3742-2/ https://www.exploit-db.com/exploits/45175/

Attack Complexity

LOW

Privileges Required

LOW

User Interaction Required

LOW

Scope

NONE

Confidentiality Impact

UNCHANGED

Integrity Impact

HIGH

Availability Impact

NONE

Base Score

NONE

Base Severity

5.5