CVE-2018-1087

MEDIUM

Description

kernel KVM before versions kernel 4.16, kernel 4.16-rc7, kernel 4.17-rc1, kernel 4.17-rc2 and kernel 4.17-rc3 is vulnerable to a flaw in the way the Linux kernel's KVM hypervisor handled exceptions delivered after a stack switch operation via Mov SS or Pop SS instructions. During the stack switch operation, the processor did not deliver interrupts and exceptions, rather they are delivered once the first instruction after the stack switch is executed. An unprivileged KVM guest user could use this flaw to crash the guest or, potentially, escalate their privileges in the guest.

References

http://www.openwall.com/lists/oss-security/2018/05/08/5

http://www.securityfocus.com/bid/104127

http://www.securitytracker.com/id/1040862

https://access.redhat.com/errata/RHSA-2018:1318

https://access.redhat.com/errata/RHSA-2018:1345

https://access.redhat.com/errata/RHSA-2018:1347

https://access.redhat.com/errata/RHSA-2018:1348

https://access.redhat.com/errata/RHSA-2018:1355

https://access.redhat.com/errata/RHSA-2018:1524

https://access.redhat.com/security/vulnerabilities/pop_ss

https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2018-1087

https://usn.ubuntu.com/3641-1/

https://usn.ubuntu.com/3641-2/

https://www.debian.org/security/2018/dsa-4196

Details

Source: MITRE

Published: 2018-05-15

Updated: 2019-10-09

Risk Information

CVSS v2.0

Base Score: 4.6

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

Impact Score: 6.4

Exploitability Score: 3.9

Severity: MEDIUM

CVSS v3.0

Base Score: 7.8

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

Impact Score: 5.9

Exploitability Score: 1.8

Severity: HIGH