CVE-2020-15566

Published Jul 7, 2020

Last updated a year ago

Overview

Description
An issue was discovered in Xen through 4.13.x, allowing guest OS users to cause a host OS crash because of incorrect error handling in event-channel port allocation. The allocation of an event-channel port may fail for multiple reasons: (1) port is already in use, (2) the memory allocation failed, or (3) the port we try to allocate is higher than what is supported by the ABI (e.g., 2L or FIFO) used by the guest or the limit set by an administrator (max_event_channels in xl cfg). Due to the missing error checks, only (1) will be considered an error. All the other cases will provide a valid port and will result in a crash when trying to access the event channel. When the administrator configured a guest to allow more than 1023 event channels, that guest may be able to crash the host. When Xen is out-of-memory, allocation of new event channels will result in crashing the host rather than reporting an error. Xen versions 4.10 and later are affected. All architectures are affected. The default configuration, when guests are created with xl/libxl, is not vulnerable, because of the default event-channel limit.
Source
cve@mitre.org
NVD status
Modified

Risk scores

CVSS 3.1

Type
Primary
Base score
6.5
Impact score
4
Exploitability score
2
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H
Severity
MEDIUM

CVSS 2.0

Type
Primary
Base score
4.7
Impact score
6.9
Exploitability score
3.4
Vector string
AV:L/AC:M/Au:N/C:N/I:N/A:C

Weaknesses

nvd@nist.gov
CWE-754

Social media

Hype score
Not currently trending

Configurations