Skip to content
OpenAdvisories
Medium USN-4750-1 10 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-gkeop, linux-gkeop-5.4, linux-hwe-5.4, linux-kvm, linux-oracle, linux-oracle-5.4, linux-raspi, linux-raspi-5.4 vulnerabilities

Published Feb 25, 2021 · Updated Jun 3, 2026

Summary

Bodong Zhao discovered a use-after-free in the Sun keyboard driver
implementation in the Linux kernel. A local attacker could use this to
cause a denial of service or possibly execute arbitrary code.
(CVE-2020-25669)

It was discovered that the jfs file system implementation in the Linux
kernel contained an out-of-bounds read vulnerability. A local attacker
could use this to possibly cause a denial of service (system crash).
(CVE-2020-27815)

Shisong Qin and Bodong Zhao discovered that Speakup screen reader driver in
the Linux kernel did not correctly handle setting line discipline in some
situations. A local attacker could use this to cause a denial of service
(system crash). (CVE-2020-27830, CVE-2020-28941)

It was discovered that an information leak existed in the syscall
implementation in the Linux kernel on 32 bit systems. A local attacker
could use this to expose sensitive information (kernel memory).
(CVE-2020-28588)

Michael Kurth and Pawel Wieczorkiewicz discovered that the Xen event
processing backend in the Linux kernel did not properly limit the number of
events queued. An attacker in a guest VM could use this to cause a denial
of service in the host OS. (CVE-2020-29568)

Olivier Benjamin and Pawel Wieczorkiewicz discovered a race condition the
Xen paravirt block backend in the Linux kernel, leading to a use-after-free
vulnerability. An attacker in a guest VM could use this to cause a denial
of service in the host OS. (CVE-2020-29569)

Jann Horn discovered that the tty subsystem of the Linux kernel did not use
consistent locking in some situations, leading to a read-after-free
vulnerability. A local attacker could use this to cause a denial of service
(system crash) or possibly expose sensitive information (kernel memory).
(CVE-2020-29660)

Jann Horn discovered a race condition in the tty subsystem of the Linux
kernel in the locking for the TIOCSPGRP ioctl(), leading to a use-after-
free vulnerability. A local attacker could use this to cause a denial of
service (system crash) or possibly execute arbitrary code. (CVE-2020-29661)

It was discovered that the netfilter subsystem in the Linux kernel did not
properly handle filter rules in some situations. A local attacker with the
CAP_NET_ADMIN capability could use this to cause a denial of service.
(CVE-2021-20177)

Fixed packages 16

ReleasePackageFixed in
Ubuntu · 18.04 LTS 18.04:LTS linux-aws-5.4 5.4.0-1038.40~18.04.1
Ubuntu · 18.04 LTS 18.04:LTS linux-azure-5.4 5.4.0-1040.42~18.04.1
Ubuntu · 18.04 LTS 18.04:LTS linux-gcp-5.4 5.4.0-1037.40~18.04.1
Ubuntu · 18.04 LTS 18.04:LTS linux-gke-5.4 5.4.0-1036.38~18.04.1
Ubuntu · 18.04 LTS 18.04:LTS linux-gkeop-5.4 5.4.0-1010.11~18.04.1
Ubuntu · 18.04 LTS 18.04:LTS linux-hwe-5.4 5.4.0-66.74~18.04.2
Ubuntu · 18.04 LTS 18.04:LTS linux-oracle-5.4 5.4.0-1038.41~18.04.1
Ubuntu · 18.04 LTS 18.04:LTS linux-raspi-5.4 5.4.0-1029.32~18.04.1
Ubuntu · 20.04 LTS 20.04:LTS linux 5.4.0-66.74
Ubuntu · 20.04 LTS 20.04:LTS linux-aws 5.4.0-1038.40
Ubuntu · 20.04 LTS 20.04:LTS linux-azure 5.4.0-1040.42
Ubuntu · 20.04 LTS 20.04:LTS linux-gcp 5.4.0-1037.40
Ubuntu · 20.04 LTS 20.04:LTS linux-gkeop 5.4.0-1010.11
Ubuntu · 20.04 LTS 20.04:LTS linux-kvm 5.4.0-1033.34
Ubuntu · 20.04 LTS 20.04:LTS linux-oracle 5.4.0-1038.41
Ubuntu · 20.04 LTS 20.04:LTS linux-raspi 5.4.0-1029.32

Vulnerabilities 10

References

  • report
    https://ubuntu.com/security/CVE-2020-25669
  • report
    https://ubuntu.com/security/CVE-2020-27815
  • report
    https://ubuntu.com/security/CVE-2020-27830
  • report
    https://ubuntu.com/security/CVE-2020-28588
  • report
    https://ubuntu.com/security/CVE-2020-28941
  • report
    https://ubuntu.com/security/CVE-2020-29568
  • report
    https://ubuntu.com/security/CVE-2020-29569
  • report
    https://ubuntu.com/security/CVE-2020-29660
  • report
    https://ubuntu.com/security/CVE-2020-29661
  • report
    https://ubuntu.com/security/CVE-2021-20177