Executive Summary



This Alert is flagged as TOP 25 Common Weakness Enumeration from CWE/SANS. For more information, you can read this.
Informations
Name CVE-2020-25600 First vendor Publication 2020-09-23
Vendor Cve Last vendor Modification 2023-11-07

Security-Database Scoring CVSS v3

Cvss vector : CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Overall CVSS Score 5.5
Base Score 5.5 Environmental Score 5.5
impact SubScore 3.6 Temporal Score 5.5
Exploitabality Sub Score 1.8
 
Attack Vector Local Attack Complexity Low
Privileges Required Low User Interaction None
Scope Unchanged Confidentiality Impact None
Integrity Impact None Availability Impact High
Calculate full CVSS 3.0 Vectors scores

Security-Database Scoring CVSS v2

Cvss vector : (AV:L/AC:L/Au:N/C:N/I:N/A:C)
Cvss Base Score 4.9 Attack Range Local
Cvss Impact Score 6.9 Attack Complexity Low
Cvss Expoit Score 3.9 Authentication None Required
Calculate full CVSS 2.0 Vectors scores

Detail

An issue was discovered in Xen through 4.14.x. Out of bounds event channels are available to 32-bit x86 domains. The so called 2-level event channel model imposes different limits on the number of usable event channels for 32-bit x86 domains vs 64-bit or Arm (either bitness) ones. 32-bit x86 domains can use only 1023 channels, due to limited space in their shared (between guest and Xen) information structure, whereas all other domains can use up to 4095 in this model. The recording of the respective limit during domain initialization, however, has occurred at a time where domains are still deemed to be 64-bit ones, prior to actually honoring respective domain properties. At the point domains get recognized as 32-bit ones, the limit didn't get updated accordingly. Due to this misbehavior in Xen, 32-bit domains (including Domain 0) servicing other domains may observe event channel allocations to succeed when they should really fail. Subsequent use of such event channels would then possibly lead to corruption of other parts of the shared info structure. An unprivileged guest may cause another domain, in particular Domain 0, to misbehave. This may lead to a Denial of Service (DoS) for the entire system. All Xen versions from 4.4 onwards are vulnerable. Xen versions 4.3 and earlier are not vulnerable. Only x86 32-bit domains servicing other domains are vulnerable. Arm systems, as well as x86 64-bit domains, are not vulnerable.

Original Source

Url : http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-25600

CWE : Common Weakness Enumeration

% Id Name
100 % CWE-787 Out-of-bounds Write (CWE/SANS Top 25)

CPE : Common Platform Enumeration

TypeDescriptionCount
Application 17
Os 1
Os 3
Os 1
Os 159

Sources (Detail)

https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedora...
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedora...
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedora...
Source Url
DEBIAN https://www.debian.org/security/2020/dsa-4769
GENTOO https://security.gentoo.org/glsa/202011-06
MISC https://xenbits.xen.org/xsa/advisory-342.html
SUSE http://lists.opensuse.org/opensuse-security-announce/2020-10/msg00008.html

Alert History

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Date Informations
2023-11-07 21:36:38
  • Multiple Updates
2023-08-02 01:53:31
  • Multiple Updates
2022-04-29 02:04:40
  • Multiple Updates
2021-09-02 01:39:29
  • Multiple Updates
2021-08-05 01:38:13
  • Multiple Updates
2021-07-21 17:23:22
  • Multiple Updates
2021-05-05 01:39:00
  • Multiple Updates
2021-05-04 13:50:20
  • Multiple Updates
2021-04-22 03:02:03
  • Multiple Updates
2021-03-27 01:34:08
  • Multiple Updates
2021-02-05 01:31:31
  • Multiple Updates
2020-11-11 12:29:36
  • Multiple Updates
2020-10-08 05:22:53
  • Multiple Updates
2020-10-05 21:23:04
  • Multiple Updates
2020-10-04 17:22:52
  • Multiple Updates
2020-10-03 09:22:53
  • Multiple Updates
2020-10-01 12:27:53
  • Multiple Updates
2020-09-27 09:22:48
  • Multiple Updates
2020-09-24 17:22:55
  • Multiple Updates
2020-09-24 05:22:57
  • First insertion