Missing Authorization in Linux kernel - CVE-2020-27777

Vulnerability identifier: #VU56242

CSH Severity: Low

CVSS v4: 8.4 [CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2020-27777

CWE-ID: CWE-862

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to the way RTAS handles 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 user could use this flaw to further increase their privileges to that of a running kernel.

Linux kernel
Amazon Linux AMI
Red Hat Enterprise Linux Workstation
Red Hat Enterprise Linux for Power, little endian
Red Hat Enterprise Linux for Scientific Computing
Red Hat Enterprise Linux for Power, big endian
Red Hat Enterprise Linux for IBM z Systems
Red Hat Enterprise Linux Desktop
Red Hat Enterprise Linux Server
CentOS
Red Hat CodeReady Linux Builder for x86_64
Red Hat CodeReady Linux Builder for ARM 64
Red Hat CodeReady Linux Builder for Power, little endian
Red Hat Enterprise Linux for ARM 64
Red Hat Enterprise Linux for x86_64
Ubuntu
openEuler
Red Hat Advanced Cluster Management for Kubernetes
Session Smart Router
kernel (Red Hat package)
linux-image-virtual-lts-xenial (Ubuntu package)
linux-image-powerpc64-smp-lts-xenial (Ubuntu package)
linux-image-powerpc64-emb-lts-xenial (Ubuntu package)
linux-image-powerpc-smp-lts-xenial (Ubuntu package)
linux-image-powerpc-e500mc-lts-xenial (Ubuntu package)
linux-image-lowlatency-lts-xenial (Ubuntu package)
linux-image-generic-lts-xenial (Ubuntu package)
linux-image-generic-lpae-lts-xenial (Ubuntu package)
linux-image-lowlatency (Ubuntu package)
linux-image-generic-lpae (Ubuntu package)
linux-image-powerpc-e500mc (Ubuntu package)
linux-image-powerpc-smp (Ubuntu package)
linux-image-powerpc64-emb (Ubuntu package)
linux-image-powerpc64-smp (Ubuntu package)
linux-image-virtual (Ubuntu package)
linux-image-generic (Ubuntu package)
linux-image-4.4.0-201-powerpc64-smp (Ubuntu package)
linux-image-4.4.0-201-powerpc64-emb (Ubuntu package)
linux-image-4.4.0-201-powerpc-smp (Ubuntu package)
linux-image-4.4.0-201-powerpc-e500mc (Ubuntu package)
linux-image-4.4.0-201-lowlatency (Ubuntu package)
linux-image-4.4.0-201-generic-lpae (Ubuntu package)
linux-image-4.4.0-201-generic (Ubuntu package)
kernel
linux-image-virtual-hwe-16.04 (Ubuntu package)
linux-image-oem (Ubuntu package)
linux-image-lowlatency-hwe-16.04 (Ubuntu package)
linux-image-generic-lpae-hwe-16.04 (Ubuntu package)
linux-image-generic-hwe-16.04 (Ubuntu package)
linux-image-4.15.0-129-generic-lpae (Ubuntu package)
linux-image-4.15.0-129-lowlatency (Ubuntu package)
linux-image-4.15.0-129-generic (Ubuntu package)
linux-image-oracle (Ubuntu package)
linux-image-4.15.0-1062-oracle (Ubuntu package)
linux-image-oracle-lts-18.04 (Ubuntu package)
linux-image-raspi2 (Ubuntu package)
linux-image-gke (Ubuntu package)
linux-image-gke-4.15 (Ubuntu package)
linux-image-4.15.0-1077-raspi2 (Ubuntu package)
linux-image-4.15.0-1077-gke (Ubuntu package)
linux-image-kvm (Ubuntu package)
linux-image-4.15.0-1082-kvm (Ubuntu package)
linux-image-aws-hwe (Ubuntu package)
linux-image-gcp (Ubuntu package)
linux-image-aws-lts-18.04 (Ubuntu package)
linux-image-4.15.0-1091-aws (Ubuntu package)
linux-image-4.15.0-1091-gcp (Ubuntu package)
linux-image-gcp-lts-18.04 (Ubuntu package)
linux-image-snapdragon (Ubuntu package)
linux-image-4.15.0-1094-snapdragon (Ubuntu package)
linux-image-azure-lts-18.04 (Ubuntu package)
linux-image-azure (Ubuntu package)
linux-image-4.15.0-1103-azure (Ubuntu package)
perf
perf-debuginfo
python2-perf
python2-perf-debuginfo
python3-perf
python3-perf-debuginfo
kernel-tools-devel
kernel-tools-debuginfo
kernel-tools
kernel-source
bpftool
bpftool-debuginfo
kernel-debuginfo
kernel-debugsource
kernel-devel
linux-image-oem-osp1 (Ubuntu package)
linux-image-5.4.0-59-generic (Ubuntu package)
linux-image-5.4.0-59-generic-lpae (Ubuntu package)
linux-image-5.4.0-59-lowlatency (Ubuntu package)
linux-image-snapdragon-hwe-18.04 (Ubuntu package)
linux-image-lowlatency-hwe-18.04 (Ubuntu package)
linux-image-generic-lpae-hwe-18.04 (Ubuntu package)
linux-image-virtual-hwe-18.04 (Ubuntu package)
linux-image-generic-hwe-18.04 (Ubuntu package)
linux-image-5.4.0-1026-raspi (Ubuntu package)
linux-image-raspi-hwe-18.04 (Ubuntu package)
linux-image-raspi (Ubuntu package)
linux-image-5.4.0-1031-kvm (Ubuntu package)
linux-image-5.4.0-1033-gcp (Ubuntu package)
linux-image-5.4.0-1033-gke (Ubuntu package)
linux-image-gke-5.4 (Ubuntu package)
linux-image-aws (Ubuntu package)
linux-image-5.4.0-1034-aws (Ubuntu package)
linux-image-5.4.0-1034-oracle (Ubuntu package)
linux-image-5.4.0-1035-azure (Ubuntu package)
linux-image-oem-20.04 (Ubuntu package)
linux-image-generic-64k (Ubuntu package)
linux-image-5.8.0-44-generic-64k (Ubuntu package)
linux-image-5.8.0-44-generic (Ubuntu package)
linux-image-5.8.0-44-lowlatency (Ubuntu package)
linux-image-5.8.0-44-generic-lpae (Ubuntu package)
linux-image-virtual-hwe-20.04 (Ubuntu package)
linux-image-lowlatency-hwe-20.04 (Ubuntu package)
linux-image-generic-lpae-hwe-20.04 (Ubuntu package)
linux-image-generic-hwe-20.04 (Ubuntu package)
linux-image-generic-64k-hwe-20.04 (Ubuntu package)
linux-image-raspi-nolpae (Ubuntu package)
linux-image-5.8.0-1016-raspi-nolpae (Ubuntu package)
linux-image-5.8.0-1016-raspi (Ubuntu package)
linux-image-5.8.0-1019-kvm (Ubuntu package)
linux-image-5.8.0-1021-oracle (Ubuntu package)
linux-image-5.8.0-1023-gcp (Ubuntu package)
linux-image-5.8.0-1023-azure (Ubuntu package)
linux-image-5.8.0-1024-aws (Ubuntu package)
IBM Qradar SIEM

Install updates from vendor's website.

Red Hat Advanced Cluster Management for Kubernetes - addressed in versions 2.1.11, 2.3.2
kernel (Red Hat package) - addressed in versions 3.10.0-1160.41.1.el7, 4.18.0-348.el8
IBM Qradar SIEM - addressed in versions 7.3.3 Fix Pack 10, 7.4.3 Fix Pack 3, 7.4.3 Fix Pack 4
linux-image-virtual-lts-xenial (Ubuntu package) - update to 4.4.0.201.176
linux-image-powerpc64-smp-lts-xenial (Ubuntu package) - update to 4.4.0.201.176
linux-image-powerpc64-emb-lts-xenial (Ubuntu package) - update to 4.4.0.201.176
linux-image-powerpc-smp-lts-xenial (Ubuntu package) - update to 4.4.0.201.176
linux-image-powerpc-e500mc-lts-xenial (Ubuntu package) - update to 4.4.0.201.176
linux-image-lowlatency-lts-xenial (Ubuntu package) - update to 4.4.0.201.176
linux-image-generic-lts-xenial (Ubuntu package) - update to 4.4.0.201.176
linux-image-generic-lpae-lts-xenial (Ubuntu package) - update to 4.4.0.201.176
linux-image-lowlatency (Ubuntu package) - addressed in versions 4.4.0.201.207, 4.15.0.129.116, 5.4.0.59.62, 5.8.0.44.49
linux-image-generic-lpae (Ubuntu package) - addressed in versions 4.4.0.201.207, 4.15.0.129.116, 5.4.0.59.62, 5.8.0.44.49
linux-image-powerpc-e500mc (Ubuntu package) - update to 4.4.0.201.207
linux-image-powerpc-smp (Ubuntu package) - update to 4.4.0.201.207
linux-image-powerpc64-emb (Ubuntu package) - update to 4.4.0.201.207
linux-image-powerpc64-smp (Ubuntu package) - update to 4.4.0.201.207
linux-image-virtual (Ubuntu package) - addressed in versions 4.4.0.201.207, 4.15.0.129.116, 5.4.0.59.62, 5.8.0.44.49
linux-image-generic (Ubuntu package) - addressed in versions 4.4.0.201.207, 4.15.0.129.116, 5.4.0.59.62, 5.8.0.44.49
linux-image-4.4.0-201-powerpc64-smp (Ubuntu package) - update to 4.4.0-201.233~14.04.1
linux-image-4.4.0-201-powerpc64-emb (Ubuntu package) - update to 4.4.0-201.233~14.04.1
linux-image-4.4.0-201-powerpc-smp (Ubuntu package) - update to 4.4.0-201.233~14.04.1
linux-image-4.4.0-201-powerpc-e500mc (Ubuntu package) - update to 4.4.0-201.233~14.04.1
linux-image-4.4.0-201-lowlatency (Ubuntu package) - update to 4.4.0-201.233~14.04.1
linux-image-4.4.0-201-generic-lpae (Ubuntu package) - update to 4.4.0-201.233~14.04.1
linux-image-4.4.0-201-generic (Ubuntu package) - update to 4.4.0-201.233~14.04.1
kernel - update to 4.14.209-117.337
linux-image-virtual-hwe-16.04 (Ubuntu package) - update to 4.15.0.129.128
linux-image-oem (Ubuntu package) - addressed in versions 4.15.0.129.128, 5.4.0.59.62, 5.4.0.59.65~18.04.54
linux-image-lowlatency-hwe-16.04 (Ubuntu package) - update to 4.15.0.129.128
linux-image-generic-lpae-hwe-16.04 (Ubuntu package) - update to 4.15.0.129.128
linux-image-generic-hwe-16.04 (Ubuntu package) - update to 4.15.0.129.128
linux-image-4.15.0-129-generic-lpae (Ubuntu package) - update to 4.15.0-129.132~16.04.1
linux-image-4.15.0-129-lowlatency (Ubuntu package) - update to 4.15.0-129.132~16.04.1
linux-image-4.15.0-129-generic (Ubuntu package) - update to 4.15.0-129.132~16.04.1
linux-image-oracle (Ubuntu package) - addressed in versions 4.15.0.1062.51, 5.4.0.1034.31, 5.4.0.1034.36~18.04.18, 5.8.0.1021.20
linux-image-4.15.0-1062-oracle (Ubuntu package) - update to 4.15.0-1062.68~16.04.1
linux-image-oracle-lts-18.04 (Ubuntu package) - update to 4.15.0.1062.72
linux-image-raspi2 (Ubuntu package) - addressed in versions 4.15.0.1077.74, 5.4.0.1026.61
linux-image-gke (Ubuntu package) - addressed in versions 4.15.0.1077.81, 4.15.0.1091.92, 5.8.0.1023.23
linux-image-gke-4.15 (Ubuntu package) - update to 4.15.0.1077.81
linux-image-4.15.0-1077-raspi2 (Ubuntu package) - update to 4.15.0-1077.82
linux-image-4.15.0-1077-gke (Ubuntu package) - update to 4.15.0-1077.82
linux-image-kvm (Ubuntu package) - addressed in versions 4.15.0.1082.78, 5.4.0.1031.29, 5.8.0.1019.21
linux-image-4.15.0-1082-kvm (Ubuntu package) - update to 4.15.0-1082.84
linux-image-aws-hwe (Ubuntu package) - update to 4.15.0.1091.85
linux-image-gcp (Ubuntu package) - addressed in versions 4.15.0.1091.92, 5.4.0.1033.21, 5.4.0.1033.42, 5.8.0.1023.23
linux-image-aws-lts-18.04 (Ubuntu package) - update to 4.15.0.1091.93
linux-image-4.15.0-1091-aws (Ubuntu package) - update to 4.15.0-1091.96~16.04.1
linux-image-4.15.0-1091-gcp (Ubuntu package) - update to 4.15.0-1091.104~16.04.1
linux-image-gcp-lts-18.04 (Ubuntu package) - update to 4.15.0.1091.109
linux-image-snapdragon (Ubuntu package) - update to 4.15.0.1094.97
linux-image-4.15.0-1094-snapdragon (Ubuntu package) - update to 4.15.0-1094.103
linux-image-azure-lts-18.04 (Ubuntu package) - update to 4.15.0.1103.76
linux-image-azure (Ubuntu package) - addressed in versions 4.15.0.1103.78, 4.15.0.1103.96, 5.4.0.1035.17, 5.4.0.1035.33, 5.8.0.1023.23
linux-image-4.15.0-1103-azure (Ubuntu package) - addressed in versions 4.15.0-1103.114~14.04.1, 4.15.0-1103.114~16.04.1
perf - update to 4.19.90-2101.1.0.0055
perf-debuginfo - update to 4.19.90-2101.1.0.0055
python2-perf - update to 4.19.90-2101.1.0.0055
python2-perf-debuginfo - update to 4.19.90-2101.1.0.0055
python3-perf - update to 4.19.90-2101.1.0.0055
python3-perf-debuginfo - update to 4.19.90-2101.1.0.0055
kernel-tools-devel - update to 4.19.90-2101.1.0.0055
kernel-tools-debuginfo - update to 4.19.90-2101.1.0.0055
kernel-tools - update to 4.19.90-2101.1.0.0055
kernel-source - update to 4.19.90-2101.1.0.0055
kernel - update to 4.19.90-2101.1.0.0055
bpftool - update to 4.19.90-2101.1.0.0055
bpftool-debuginfo - update to 4.19.90-2101.1.0.0055
kernel-debuginfo - update to 4.19.90-2101.1.0.0055
kernel-debugsource - update to 4.19.90-2101.1.0.0055
kernel-devel - update to 4.19.90-2101.1.0.0055
linux-image-oem-osp1 (Ubuntu package) - addressed in versions 5.4.0.59.62, 5.4.0.59.65~18.04.54
linux-image-5.4.0-59-generic (Ubuntu package) - addressed in versions 5.4.0-59.65, 5.4.0-59.65~18.04.1
linux-image-5.4.0-59-generic-lpae (Ubuntu package) - addressed in versions 5.4.0-59.65, 5.4.0-59.65~18.04.1
linux-image-5.4.0-59-lowlatency (Ubuntu package) - addressed in versions 5.4.0-59.65, 5.4.0-59.65~18.04.1
linux-image-snapdragon-hwe-18.04 (Ubuntu package) - update to 5.4.0.59.65~18.04.54
linux-image-lowlatency-hwe-18.04 (Ubuntu package) - update to 5.4.0.59.65~18.04.54
linux-image-generic-lpae-hwe-18.04 (Ubuntu package) - update to 5.4.0.59.65~18.04.54
linux-image-virtual-hwe-18.04 (Ubuntu package) - update to 5.4.0.59.65~18.04.54
linux-image-generic-hwe-18.04 (Ubuntu package) - update to 5.4.0.59.65~18.04.54
linux-image-5.4.0-1026-raspi (Ubuntu package) - addressed in versions 5.4.0-1026.29, 5.4.0-1026.29~18.04.1
linux-image-raspi-hwe-18.04 (Ubuntu package) - update to 5.4.0.1026.30
linux-image-raspi (Ubuntu package) - addressed in versions 5.4.0.1026.61, 5.8.0.1016.19
linux-image-5.4.0-1031-kvm (Ubuntu package) - update to 5.4.0-1031.32
linux-image-5.4.0-1033-gcp (Ubuntu package) - addressed in versions 5.4.0-1033.35, 5.4.0-1033.35~18.04.1
linux-image-5.4.0-1033-gke (Ubuntu package) - update to 5.4.0-1033.35~18.04.1
linux-image-gke-5.4 (Ubuntu package) - update to 5.4.0.1033.35~18.04.2
linux-image-aws (Ubuntu package) - addressed in versions 5.4.0.1034.19, 5.4.0.1034.35, 5.8.0.1024.26
linux-image-5.4.0-1034-aws (Ubuntu package) - addressed in versions 5.4.0-1034.35, 5.4.0-1034.35~18.04.1
linux-image-5.4.0-1034-oracle (Ubuntu package) - addressed in versions 5.4.0-1034.36, 5.4.0-1034.36~18.04.1
linux-image-5.4.0-1035-azure (Ubuntu package) - addressed in versions 5.4.0-1035.36, 5.4.0-1035.36~18.04.1
Session Smart Router - addressed in versions 5.4.7, 5.5.3
linux-image-oem-20.04 (Ubuntu package) - update to 5.8.0.44.49
linux-image-generic-64k (Ubuntu package) - update to 5.8.0.44.49
linux-image-5.8.0-44-generic-64k (Ubuntu package) - update to 5.8.0-44.50
linux-image-5.8.0-44-generic (Ubuntu package) - update to 5.8.0-44.50~20.04.1
linux-image-5.8.0-44-lowlatency (Ubuntu package) - update to 5.8.0-44.50~20.04.1
linux-image-5.8.0-44-generic-lpae (Ubuntu package) - update to 5.8.0-44.50~20.04.1
linux-image-virtual-hwe-20.04 (Ubuntu package) - update to 5.8.0.44.50~20.04.30
linux-image-lowlatency-hwe-20.04 (Ubuntu package) - update to 5.8.0.44.50~20.04.30
linux-image-generic-lpae-hwe-20.04 (Ubuntu package) - update to 5.8.0.44.50~20.04.30
linux-image-generic-hwe-20.04 (Ubuntu package) - update to 5.8.0.44.50~20.04.30
linux-image-generic-64k-hwe-20.04 (Ubuntu package) - update to 5.8.0.44.50~20.04.30
linux-image-raspi-nolpae (Ubuntu package) - update to 5.8.0.1016.19
linux-image-5.8.0-1016-raspi-nolpae (Ubuntu package) - update to 5.8.0-1016.19
linux-image-5.8.0-1016-raspi (Ubuntu package) - update to 5.8.0-1016.19
linux-image-5.8.0-1019-kvm (Ubuntu package) - update to 5.8.0-1019.21
linux-image-5.8.0-1021-oracle (Ubuntu package) - update to 5.8.0-1021.22
linux-image-5.8.0-1023-gcp (Ubuntu package) - update to 5.8.0-1023.24
linux-image-5.8.0-1023-azure (Ubuntu package) - update to 5.8.0-1023.25
linux-image-5.8.0-1024-aws (Ubuntu package) - update to 5.8.0-1024.26

• 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

• Privilege escalation in Linux kernel
• Red Hat Enterprise Linux 7 update for kernel
• CentOS 7 update for kernel
• Multiple vulnerabilities in Red Hat Advanced Cluster Management for Kubernetes
• Multiple vulnerabilities in IBM QRadar SIEM
• Multiple vulnerabilities in IBM QRadar SIEM
• Multiple vulnerabilities in IBM QRadar SIEM
• Multiple vulnerabilities in Juniper Networks Session Smart Router
• Multiple vulnerabilities in Red Hat Advanced Cluster Management for Kubernetes 2.3
• Red Hat Enterprise Linux 8 update for kernel
• Ubuntu update for linux
• Ubuntu update for linux
• Ubuntu update for linux
• Ubuntu update for linux
• Amazon Linux AMI update for kernel
• openEuler update for kernel