5.5
MEDIUM
CVE-2020-29566
Xen x86 HVM Guest Denial of Service Stack Overflow Vulnerability
Description

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.

INFO

Published Date :

Dec. 15, 2020, 5:15 p.m.

Last Modified :

Nov. 7, 2023, 3:21 a.m.

Remotely Exploitable :

No

Impact Score :

3.6

Exploitability Score :

1.8
Affected Products

The following products are affected by CVE-2020-29566 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Fedoraproject fedora
1 Debian debian_linux
1 Xen xen
References to Advisories, Solutions, and Tools

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2020-29566 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2020-29566 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by [email protected]

    May. 14, 2024

    Action Type Old Value New Value
  • CVE Modified by [email protected]

    Nov. 07, 2023

    Action Type Old Value New Value
    Added Reference MITRE https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/OBLV6L6Q24PPQ2CRFXDX4Q76KU776GKI/ [No types assigned]
    Added Reference MITRE https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2C6M6S3CIMEBACH6O7V4H2VDANMO6TVA/ [No types assigned]
    Removed Reference MITRE https://lists.fedoraproject.org/archives/list/[email protected]/message/OBLV6L6Q24PPQ2CRFXDX4Q76KU776GKI/
    Removed Reference MITRE https://lists.fedoraproject.org/archives/list/[email protected]/message/2C6M6S3CIMEBACH6O7V4H2VDANMO6TVA/
  • Modified Analysis by [email protected]

    Dec. 10, 2021

    Action Type Old Value New Value
    Changed Reference Type https://security.gentoo.org/glsa/202107-30 No Types Assigned https://security.gentoo.org/glsa/202107-30 Third Party Advisory
  • CVE Modified by [email protected]

    Jul. 12, 2021

    Action Type Old Value New Value
    Added Reference https://security.gentoo.org/glsa/202107-30 [No Types Assigned]
  • Modified Analysis by [email protected]

    Mar. 16, 2021

    Action Type Old Value New Value
    Changed Reference Type https://lists.fedoraproject.org/archives/list/[email protected]/message/2C6M6S3CIMEBACH6O7V4H2VDANMO6TVA/ No Types Assigned https://lists.fedoraproject.org/archives/list/[email protected]/message/2C6M6S3CIMEBACH6O7V4H2VDANMO6TVA/ Mailing List, Third Party Advisory
    Changed Reference Type https://lists.fedoraproject.org/archives/list/[email protected]/message/OBLV6L6Q24PPQ2CRFXDX4Q76KU776GKI/ No Types Assigned https://lists.fedoraproject.org/archives/list/[email protected]/message/OBLV6L6Q24PPQ2CRFXDX4Q76KU776GKI/ Mailing List, Third Party Advisory
    Added CPE Configuration OR *cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:* *cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*
  • CVE Modified by [email protected]

    Dec. 25, 2020

    Action Type Old Value New Value
    Added Reference https://lists.fedoraproject.org/archives/list/[email protected]/message/OBLV6L6Q24PPQ2CRFXDX4Q76KU776GKI/ [No Types Assigned]
    Added Reference https://lists.fedoraproject.org/archives/list/[email protected]/message/2C6M6S3CIMEBACH6O7V4H2VDANMO6TVA/ [No Types Assigned]
  • Initial Analysis by [email protected]

    Dec. 18, 2020

    Action Type Old Value New Value
    Added CVSS V2 NIST (AV:L/AC:L/Au:N/C:N/I:N/A:C)
    Added CVSS V3.1 NIST AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
    Changed Reference Type https://www.debian.org/security/2020/dsa-4812 No Types Assigned https://www.debian.org/security/2020/dsa-4812 Third Party Advisory
    Changed Reference Type https://xenbits.xenproject.org/xsa/advisory-348.html No Types Assigned https://xenbits.xenproject.org/xsa/advisory-348.html Patch, Vendor Advisory
    Added CWE NIST CWE-674
    Added CPE Configuration OR *cpe:2.3:o:xen:xen:*:*:*:*:*:*:x86:* versions up to (including) 4.14.0
    Added CPE Configuration OR *cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*
  • CVE Modified by [email protected]

    Dec. 16, 2020

    Action Type Old Value New Value
    Added Reference https://www.debian.org/security/2020/dsa-4812 [No Types Assigned]
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2020-29566 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2020-29566 weaknesses.

Exploit Prediction

EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days.

0.05 }} 0.00%

score

0.16459

percentile

CVSS31 - Vulnerability Scoring System
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality
Integrity
Availability