Homepage
About Snyk

Uncontrolled Recursion Affecting xen package, versions <4.14.1-r0

0.0
medium

Snyk CVSS

    Attack Complexity Low
    Availability High

    Threat Intelligence

    EPSS 0.05% (18th percentile)
Expand this section
NVD
5.5 medium
Expand this section
SUSE
6.5 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-ALPINE314-XEN-1308547
  • published 1 Jan 2021
  • disclosed 15 Dec 2020
Report a new vulnerability Found a mistake?

Introduced: 15 Dec 2020

CVE-2020-29566 Open this link in a new tab
CWE-674 Open this link in a new tab

How to fix?

Upgrade Alpine:3.14 xen to version 4.14.1-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:3.14 relevant fixed versions and status.

An issue was discovered in Xen through 4.14.x. When they require assistance from the device model, x86 HVM guests must be temporarily de-scheduled. The device model will signal Xen when it has completed its operation, via an event channel, so that the relevant vCPU is rescheduled. If the device model were to signal Xen without having actually completed the operation, the de-schedule / re-schedule cycle would repeat. If, in addition, Xen is resignalled very quickly, the re-schedule may occur before the de-schedule was fully complete, triggering a shortcut. This potentially repeating process uses ordinary recursive function calls, and thus could result in a stack overflow. A malicious or buggy stubdomain serving a HVM guest can cause Xen to crash, resulting in a Denial of Service (DoS) to the entire host. Only x86 systems are affected. Arm systems are not affected. Only x86 stubdomains serving HVM guests can exploit the vulnerability.