[USN-5082-1] Linux kernel (OEM) vulnerabilities
steve.beattie at canonical.com
Thu Sep 16 17:20:33 UTC 2021
Ubuntu Security Notice USN-5082-1
September 16, 2021
A security issue affects these releases of Ubuntu and its derivatives:
- Ubuntu 20.04 LTS
Several security issues were fixed in the Linux kernel.
- linux-oem-5.13: Linux kernel for OEM systems
Maxim Levitsky and Paolo Bonzini discovered that the KVM hypervisor
implementation for AMD processors in the Linux kernel allowed a guest VM to
disable restrictions on VMLOAD/VMSAVE in a nested guest. An attacker in a
guest VM could use this to read or write portions of the host's physical
Maxim Levitsky discovered that the KVM hypervisor implementation for AMD
processors in the Linux kernel did not properly prevent a guest VM from
enabling AVIC in nested guest VMs. An attacker in a guest VM could use this
to write to portions of the host's physical memory. (CVE-2021-3653)
Norbert Slusarek discovered a race condition in the CAN BCM networking
protocol of the Linux kernel leading to multiple use-after-free
vulnerabilities. A local attacker could use this issue to execute arbitrary
The problem can be corrected by updating your system to the following
Ubuntu 20.04 LTS:
After a standard system update you need to reboot your computer to make
all the necessary changes.
ATTENTION: Due to an unavoidable ABI change the kernel updates have
been given a new version number, which requires you to recompile and
reinstall all third party kernel modules you might have installed.
Unless you manually uninstalled the standard kernel metapackages
(e.g. linux-generic, linux-generic-lts-RELEASE, linux-virtual,
linux-powerpc), a standard system upgrade will automatically perform
this as well.
CVE-2021-3609, CVE-2021-3653, CVE-2021-3656
-------------- next part --------------
A non-text attachment was scrubbed...
Size: 833 bytes
Desc: not available
More information about the ubuntu-security-announce