CVE-2020-27777 Information

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.

CVSS Vector

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

Reference

https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git/commit/?h=next&id=bd59380c5ba4147dcbaad3e582b55ccfd120b764 https://www.openwall.com/lists/oss-security/2020/11/23/2 https://www.openwall.com/lists/oss-security/2020/10/09/1 https://bugzilla.redhat.com/show_bug.cgi?id=1900844

Attack Complexity

LOW

Privileges Required

HIGH

User Interaction Required

HIGH

Scope

NONE

Confidentiality Impact

UNCHANGED

Integrity Impact

HIGH

Availability Impact

HIGH

Base Score

HIGH

Base Severity

6.7