Read the docs
TI-2020-16862 Aliases CVE-2020-27777GHSA-w5hm-w8cx-wrwr

Missing authorization in kernel

Priority LOW 30CWE-862Published · Updated

Key facts

Attack vector
Local
Privileges required
High
User interaction
None
Attack complexity
Low
Impact type
Security bypass
Confidentiality · integrity · availability
High · High · High
Fix status
Partial Red Hat: 9 fixed, 3 without a fix

Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-862.

Summary

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.

Why it matters now

EPSS 0.00476 41st percentileScored 2026-11-07
Public exploit Yes 2 exploit referencesTagged by NVD
Fix Partial Red Hat: 2 advisoriesRed Hat: 9 fixed, 3 without a fix

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
—kernelkernel 5.10-rc1—No fix listedCNA
  • kernel Vendor— Affected kernel 5.10-rc1 Fixed in — No fix listed CNA

CPE configurations NVD · 8

CPEVersionsRoleVendor
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*before 4.14.204; 4.15 to before 4.19.155; 4.20 to before 5.4.75; 5.5 to before 5.9.5VulnerableLinux
cpe:2.3:a:redhat:openshift_container_platform:4.4:*:*:*:*:*:*:*4.4VulnerableRed Hat
cpe:2.3:a:redhat:openshift_container_platform:4.5:*:*:*:*:*:*:*4.5VulnerableRed Hat
cpe:2.3:a:redhat:openshift_container_platform:4.6:*:*:*:*:*:*:*4.6VulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux:5.0:*:*:*:*:*:*:*5.0VulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux:6.0:*:*:*:*:*:*:*6.0VulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*7.0VulnerableRed Hat
cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*8.0VulnerableRed Hat
  • cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions before 4.14.204; 4.15 to before 4.19.155; 4.20 to before 5.4.75; 5.5 to before 5.9.5 Vulnerable ·Linux
  • cpe:2.3:a:redhat:openshift_container_platform:4.4:*:*:*:*:*:*:* Versions 4.4 Vulnerable ·Red Hat
  • cpe:2.3:a:redhat:openshift_container_platform:4.5:*:*:*:*:*:*:* Versions 4.5 Vulnerable ·Red Hat
  • cpe:2.3:a:redhat:openshift_container_platform:4.6:*:*:*:*:*:*:* Versions 4.6 Vulnerable ·Red Hat
  • cpe:2.3:o:redhat:enterprise_linux:5.0:*:*:*:*:*:*:* Versions 5.0 Vulnerable ·Red Hat
  • cpe:2.3:o:redhat:enterprise_linux:6.0:*:*:*:*:*:*:* Versions 6.0 Vulnerable ·Red Hat
  • cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:* Versions 7.0 Vulnerable ·Red Hat
  • cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:* Versions 8.0 Vulnerable ·Red Hat

Remediation

Red Hat 2 advisories

  • RHSA-2021:4356 Released 2021-11-09 · Red Hat rating Moderate
    kernel security, bug fix, and enhancement update
    • Red Hat CodeReady Linux Builder (v. 8) kernel-tools-libs-devel-4.18.0-348.el8
    • Red Hat Enterprise Linux BaseOS (v. 8) bpftool-4.18.0-348.el8, kernel-4.18.0-348.el8, kernel-abi-stablelists-4.18.0-348.el8 +19
  • RHSA-2021:3327 Released 2021-08-31 · Red Hat rating Important
    kernel security and bug fix update
    • Red Hat Enterprise Linux Client (v. 7) bpftool-3.10.0-1160.41.1.el7, kernel-3.10.0-1160.41.1.el7, kernel-abi-whitelists-3.10.0-1160.41.1.el7 +8
    • Red Hat Enterprise Linux Client Optional (v. 7) kernel-tools-libs-devel-3.10.0-1160.41.1.el7
    • Red Hat Enterprise Linux ComputeNode Optional (v. 7) kernel-tools-libs-devel-3.10.0-1160.41.1.el7
    • Red Hat Enterprise Linux Server (v. 7) bpftool-3.10.0-1160.41.1.el7, kernel-3.10.0-1160.41.1.el7, kernel-abi-whitelists-3.10.0-1160.41.1.el7 +11
    • Red Hat Enterprise Linux Server Optional (v. 7) kernel-debug-devel-3.10.0-1160.41.1.el7, kernel-tools-libs-devel-3.10.0-1160.41.1.el7
    • Red Hat Enterprise Linux Workstation (v. 7) bpftool-3.10.0-1160.41.1.el7, kernel-3.10.0-1160.41.1.el7, kernel-abi-whitelists-3.10.0-1160.41.1.el7 +8
    • Red Hat Enterprise Linux Workstation Optional (v. 7) kernel-tools-libs-devel-3.10.0-1160.41.1.el7

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 5AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux 6AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux 7AffectedNo fix planned: Will not fix
Red Hat CodeReady Linux Builder (v. 8)Fixed RHSA-2021:4356
Red Hat Enterprise Linux BaseOS (v. 8)Fixed RHSA-2021:4356
Red Hat Enterprise Linux Client (v. 7)Fixed RHSA-2021:3327
Red Hat Enterprise Linux Client Optional (v. 7)Fixed RHSA-2021:3327
Red Hat Enterprise Linux ComputeNode Optional (v. 7)Fixed RHSA-2021:3327
Red Hat Enterprise Linux Server (v. 7)Fixed RHSA-2021:3327
Red Hat Enterprise Linux Server Optional (v. 7)Fixed RHSA-2021:3327
Red Hat Enterprise Linux Workstation (v. 7)Fixed RHSA-2021:3327
Red Hat Enterprise Linux Workstation Optional (v. 7)Fixed RHSA-2021:3327
Not affected: 2 products
  • Red Hat Enterprise Linux 7
  • Red Hat Enterprise Linux 8

Timeline

  1. 2026-10-02 Threatist record created from CVE-2020-27777
  2. 2026-10-03 Alias added: GHSA-w5hm-w8cx-wrwr

References

Exploit 2

Patch 1

Advisory 1

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences