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USN-4679-1 Not scored

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

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)

Exploit probability Not scored
Published January 6, 2021
Required by Not available
Last source change June 3, 2026

02 / AFFECTED SOFTWARE

Affected packages

Ubuntu:18.04:LTS linux-aws-5.4

9 explicit affected versions

Ubuntu:18.04:LTS linux-azure-5.4

8 explicit affected versions

Ubuntu:18.04:LTS linux-gcp-5.4

9 explicit affected versions

Ubuntu:18.04:LTS linux-gke-5.4

5 explicit affected versions

Ubuntu:18.04:LTS linux-hwe-5.4

13 explicit affected versions

Ubuntu:18.04:LTS linux-oracle-5.4

9 explicit affected versions

Ubuntu:18.04:LTS linux-raspi-5.4

9 explicit affected versions

Ubuntu:20.04:LTS linux

25 explicit affected versions

Ubuntu:20.04:LTS linux-aws

21 explicit affected versions

Ubuntu:20.04:LTS linux-azure

18 explicit affected versions

Ubuntu:20.04:LTS linux-gcp

19 explicit affected versions

Ubuntu:20.04:LTS linux-kvm

18 explicit affected versions

Ubuntu:20.04:LTS linux-oracle

19 explicit affected versions

Ubuntu:20.04:LTS linux-raspi

13 explicit affected versions

03 / CONNECTIONS

Connected vulnerabilities

04 / EVIDENCE

Source records

Open Source Vulnerabilities USN-4679-1

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)

View original source

05 / REFERENCES

Further evidence