CVE-2017-7518 Information

Description

A flaw was found in the Linux kernel before version 4.12 in the way the KVM module processed the trap flag(TF) bit in EFLAGS during emulation of the syscall instruction which leads to a debug exception(DB) being raised in the guest stack. A user/process inside a guest could use this flaw to potentially escalate their privileges inside the guest. Linux guests are not affected by this.

CVSS Vector

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

Reference

http://www.openwall.com/lists/oss-security/2017/06/23/5 http://www.securityfocus.com/bid/99263 http://www.securitytracker.com/id/1038782 https://access.redhat.com/articles/3290921 https://access.redhat.com/errata/RHSA-2018:0395 https://access.redhat.com/errata/RHSA-2018:0412 https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2017-7518 https://usn.ubuntu.com/3619-1/ https://usn.ubuntu.com/3619-2/ https://usn.ubuntu.com/3754-1/ https://www.debian.org/security/2017/dsa-3981 https://www.spinics.net/lists/kvm/msg151817.html

Attack Complexity

LOW

Privileges Required

LOW

User Interaction Required

LOW

Scope

NONE

Confidentiality Impact

UNCHANGED

Integrity Impact

HIGH

Availability Impact

HIGH

Base Score

HIGH

Base Severity

7.8