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.
CVE-2020-27777 - Medium Severity Vulnerability
Julia Cartwright's fork of linux-stable-rt.git
Library home page: https://git.kernel.org/pub/scm/linux/kernel/git/julia/linux-stable-rt.git
Found in HEAD commit: 5efa23eac0f04571d486a6f7706fccc426b46cac
Found in base branch: master
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.
Publish Date: 2020-12-15
URL: CVE-2020-27777
Base Score Metrics: - Exploitability Metrics: - Attack Vector: Local - Attack Complexity: Low - Privileges Required: High - User Interaction: None - Scope: Unchanged - Impact Metrics: - Confidentiality Impact: High - Integrity Impact: High - Availability Impact: High
For more information on CVSS3 Scores, click here.Type: Upgrade version
Origin: https://www.linuxkernelcves.com/cves/CVE-2020-27777
Release Date: 2020-12-15
Fix Resolution: v4.14.204, v4.19.155, v5.4.75, v5.9.5,v5.10-rc1
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