CVE-2019-19580 Information

Description

An issue was discovered in Xen through 4.12.x allowing x86 PV guest OS users to gain host OS privileges by leveraging race conditions in pagetable promotion and demotion operations because of an incomplete fix for CVE-2019-18421. XSA-299 addressed several critical issues in restartable PV type change operations. Despite extensive testing and auditing some corner cases were missed. A malicious PV guest administrator may be able to escalate their privilege to that of the host. All security-supported versions of Xen are vulnerable. Only x86 systems are affected. Arm systems are not affected. Only x86 PV guests can leverage the vulnerability. x86 HVM and PVH guests cannot leverage the vulnerability. Note that these attacks require very precise timing which may be difficult to exploit in practice.

CVSS Vector

CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H

Reference

http://lists.opensuse.org/opensuse-security-announce/2020-01/msg00011.html https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/34HBFTYNMQMWIO2GGK7DB6KV4M6R5YPV/ https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/D5R73AYE53QA32KTMHUVKCX6E52CIS43/ https://seclists.org/bugtraq/2020/Jan/21 https://security.gentoo.org/glsa/202003-56 https://www.debian.org/security/2020/dsa-4602 https://xenbits.xen.org/xsa/advisory-310.html

Attack Complexity

HIGH

Privileges Required

HIGH

User Interaction Required

HIGH

Scope

NONE

Confidentiality Impact

UNCHANGED

Integrity Impact

HIGH

Availability Impact

HIGH

Base Score

HIGH

Base Severity

6.6