Race Condition Affecting xen package, versions <4.13.0-r0


0.0
medium

Snyk CVSS

    Attack Complexity High
    Privileges Required High
    Confidentiality High
    Integrity High
    Availability High

    Threat Intelligence

    EPSS 0.3% (69th percentile)
Expand this section
NVD
6.6 medium
Expand this section
SUSE
6.6 medium

Do your applications use this vulnerable package?

In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.

Test your applications
  • Snyk ID SNYK-ALPINE315-XEN-1928717
  • published 21 Jul 2020
  • disclosed 11 Dec 2019

How to fix?

Upgrade Alpine:3.15 xen to version 4.13.0-r0 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream xen package and not the xen package as distributed by Alpine. See How to fix? for Alpine:3.15 relevant fixed versions and status.

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.