CVE-2020-27777

medium

Description

A flaw was found in the way RTAS handled memory accesses in userspace to kernel communication. On a locked down (usually due to Secure Boot) guest system running on top of PowerVM or KVM hypervisors (pseries platform) a root like local user could use this flaw to further increase their privileges to that of a running kernel.

References

https://bugzilla.redhat.com/show_bug.cgi?id=1900844

https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git/commit/?h=next&id=bd59380c5ba4147dcbaad3e582b55ccfd120b764

https://www.openwall.com/lists/oss-security/2020/10/09/1

https://www.openwall.com/lists/oss-security/2020/11/23/2

Details

Source: MITRE

Published: 2020-12-15

Updated: 2020-12-22

Type: CWE-862

Risk Information

CVSS v2

Base Score: 7.2

Vector: AV:L/AC:L/Au:N/C:C/I:C/A:C

Impact Score: 10

Exploitability Score: 3.9

Severity: HIGH

CVSS v3

Base Score: 6.7

Vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H

Impact Score: 5.9

Exploitability Score: 0.8

Severity: MEDIUM