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OpenAdvisories
Unscored USN-4679-1 6 CVEs

linux, linux-aws, linux-aws-5.4, linux-azure, linux-azure-5.4, linux-gcp, linux-gcp-5.4, linux-gke-5.4, linux-hwe-5.4, linux-kvm, linux-oracle, linux-oracle-5.4, linux-raspi, linux-raspi-5.4 vulnerabilities

Published Jan 6, 2021 · Updated Jun 3, 2026

Summary

It was discovered that the console keyboard driver in the Linux kernel
contained a race condition. A local attacker could use this to expose
sensitive information (kernel memory). (CVE-2020-25656)

Minh Yuan discovered that the tty driver in the Linux kernel contained race
conditions when handling fonts. A local attacker could possibly use this to
expose sensitive information (kernel memory). (CVE-2020-25668)

Kiyin (尹亮) discovered that the perf subsystem in the Linux kernel did
not properly deallocate memory in some situations. A privileged attacker
could use this to cause a denial of service (kernel memory exhaustion).
(CVE-2020-25704)

Jinoh Kang discovered that the Xen event channel infrastructure in the
Linux kernel contained a race condition. An attacker in guest could
possibly use this to cause a denial of service (dom0 crash).
(CVE-2020-27675)

Daniel Axtens discovered that PowerPC RTAS implementation in the Linux
kernel did not properly restrict memory accesses in some situations. A
privileged local attacker could use this to arbitrarily modify kernel
memory, potentially bypassing kernel lockdown restrictions.
(CVE-2020-27777)

Minh Yuan discovered that the framebuffer console driver in the Linux
kernel did not properly handle fonts in some conditions. A local attacker
could use this to cause a denial of service (system crash) or possibly
expose sensitive information (kernel memory). (CVE-2020-28974)

Fixed packages 14

ReleasePackageFixed in
Ubuntu · 18.04 LTS 18.04:LTS linux-aws-5.4 5.4.0-1034.35~18.04.1
Ubuntu · 18.04 LTS 18.04:LTS linux-azure-5.4 5.4.0-1035.36~18.04.1
Ubuntu · 18.04 LTS 18.04:LTS linux-gcp-5.4 5.4.0-1033.35~18.04.1
Ubuntu · 18.04 LTS 18.04:LTS linux-gke-5.4 5.4.0-1033.35~18.04.1
Ubuntu · 18.04 LTS 18.04:LTS linux-hwe-5.4 5.4.0-59.65~18.04.1
Ubuntu · 18.04 LTS 18.04:LTS linux-oracle-5.4 5.4.0-1034.36~18.04.1
Ubuntu · 18.04 LTS 18.04:LTS linux-raspi-5.4 5.4.0-1026.29~18.04.1
Ubuntu · 20.04 LTS 20.04:LTS linux 5.4.0-59.65
Ubuntu · 20.04 LTS 20.04:LTS linux-aws 5.4.0-1034.35
Ubuntu · 20.04 LTS 20.04:LTS linux-azure 5.4.0-1035.36
Ubuntu · 20.04 LTS 20.04:LTS linux-gcp 5.4.0-1033.35
Ubuntu · 20.04 LTS 20.04:LTS linux-kvm 5.4.0-1031.32
Ubuntu · 20.04 LTS 20.04:LTS linux-oracle 5.4.0-1034.36
Ubuntu · 20.04 LTS 20.04:LTS linux-raspi 5.4.0-1026.29

Vulnerabilities 6

References

  • report
    https://ubuntu.com/security/CVE-2020-25656
  • report
    https://ubuntu.com/security/CVE-2020-25668
  • report
    https://ubuntu.com/security/CVE-2020-25704
  • report
    https://ubuntu.com/security/CVE-2020-27675
  • report
    https://ubuntu.com/security/CVE-2020-27777
  • report
    https://ubuntu.com/security/CVE-2020-28974