Protect yourself against future threats.
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA256
===========================================================================
AUSCERT External Security Bulletin Redistribution
ESB-2021.1945
USN-4983-1: Linux kernel (OEM) vulnerabilities
4 June 2021
===========================================================================
AusCERT Security Bulletin Summary
---------------------------------
Product: linux kernel (OEM)
Publisher: Ubuntu
Operating System: Ubuntu
Impact/Access: Execute Arbitrary Code/Commands -- Existing Account
Increased Privileges -- Existing Account
Denial of Service -- Existing Account
Access Confidential Data -- Existing Account
Reduced Security -- Existing Account
Resolution: Patch/Upgrade
CVE Names: CVE-2021-33200 CVE-2021-31829 CVE-2021-29155
CVE-2021-3501
Reference: ESB-2021.1919
ESB-2021.1868
ESB-2021.1663
Original Bulletin:
https://ubuntu.com/security/notices/USN-4983-1
- --------------------------BEGIN INCLUDED TEXT--------------------
USN-4983-1: Linux kernel (OEM) vulnerabilities
03 June 2021
Several security issues were fixed in the Linux kernel.
Releases
o Ubuntu 20.04 LTS
Packages
o linux-oem-5.10 - Linux kernel for OEM systems
Details
Piotr Krysiuk discovered that the eBPF implementation in the Linux kernel
did not properly enforce limits for pointer operations. A local attacker
could use this to cause a denial of service (system crash) or possibly
execute arbitrary code. ( CVE-2021-33200 )
Piotr Krysiuk and Benedict Schlueter discovered that the eBPF
implementation in the Linux kernel performed out of bounds speculation on
pointer arithmetic. A local attacker could use this to expose sensitive
information. ( CVE-2021-29155 )
Piotr Krysiuk discovered that the eBPF implementation in the Linux kernel
did not properly prevent speculative loads in certain situations. A local
attacker could use this to expose sensitive information (kernel memory).
( CVE-2021-31829 )
Reiji Watanabe discovered that the KVM VMX implementation in the Linux
kernel did not properly prevent user space from tampering with an array
index value, leading to a potential out-of-bounds write. A local attacker
could use this to cause a denial of service (system crash) or possibly
execute arbitrary code. ( CVE-2021-3501 )
Update instructions
The problem can be corrected by updating your system to the following package
versions:
Ubuntu 20.04
o linux-image-oem-20.04b - 5.10.0.1029.30
o linux-image-oem-20.04 - 5.10.0.1029.30
o linux-image-5.10.0-1029-oem - 5.10.0-1029.30
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.
References
o CVE-2021-29155
o CVE-2021-3501
o CVE-2021-31829
o CVE-2021-33200
Related notices
o USN-4977-1 : linux-image-5.11.0-1008-kvm, linux-image-aws,
linux-image-generic-hwe-20.04, linux-oracle, linux-image-5.11.0-1008-gcp,
linux, linux-image-generic-64k-hwe-20.04-edge,
linux-image-lowlatency-hwe-20.04, linux-image-5.11.0-1008-aws,
linux-image-oracle, linux-image-5.11.0-1009-raspi, linux-kvm,
linux-image-5.11.0-18-generic-lpae, linux-image-5.11.0-1006-azure,
linux-image-gcp, linux-image-generic, linux-image-kvm, linux-image-gke,
linux-image-5.11.0-1009-raspi-nolpae, linux-image-lowlatency,
linux-image-5.11.0-18-generic, linux-image-5.11.0-18-lowlatency,
linux-image-5.11.0-18-generic-64k, linux-image-oem-20.04,
linux-image-raspi-nolpae, linux-gcp, linux-image-generic-lpae-hwe-20.04,
linux-image-generic-hwe-20.04-edge, linux-raspi, linux-image-raspi,
linux-azure, linux-image-virtual-hwe-20.04-edge,
linux-image-generic-64k-hwe-20.04, linux-image-5.11.0-1007-oracle,
linux-image-lowlatency-hwe-20.04-edge, linux-image-virtual-hwe-20.04,
linux-image-azure, linux-image-generic-lpae, linux-image-virtual,
linux-aws, linux-image-generic-lpae-hwe-20.04-edge, linux-image-generic-64k
- --------------------------END INCLUDED TEXT--------------------
You have received this e-mail bulletin as a result of your organisation's
registration with AusCERT. The mailing list you are subscribed to is
maintained within your organisation, so if you do not wish to continue
receiving these bulletins you should contact your local IT manager. If
you do not know who that is, please send an email to auscert@auscert.org.au
and we will forward your request to the appropriate person.
NOTE: Third Party Rights
This security bulletin is provided as a service to AusCERT's members. As
AusCERT did not write the document quoted above, AusCERT has had no control
over its content. The decision to follow or act on information or advice
contained in this security bulletin is the responsibility of each user or
organisation, and should be considered in accordance with your organisation's
site policies and procedures. AusCERT takes no responsibility for consequences
which may arise from following or acting on information or advice contained in
this security bulletin.
NOTE: This is only the original release of the security bulletin. It may
not be updated when updates to the original are made. If downloading at
a later date, it is recommended that the bulletin is retrieved directly
from the author's website to ensure that the information is still current.
Contact information for the authors of the original document is included
in the Security Bulletin above. If you have any questions or need further
information, please contact them directly.
Previous advisories and external security bulletins can be retrieved from:
https://www.auscert.org.au/bulletins/
===========================================================================
Australian Computer Emergency Response Team
The University of Queensland
Brisbane
Qld 4072
Internet Email: auscert@auscert.org.au
Facsimile: (07) 3365 7031
Telephone: (07) 3365 4417 (International: +61 7 3365 4417)
AusCERT personnel answer during Queensland business hours
which are GMT+10:00 (AEST).
On call after hours for member emergencies only.
===========================================================================
-----BEGIN PGP SIGNATURE-----
Comment: http://www.auscert.org.au/render.html?it=1967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=LpI6
-----END PGP SIGNATURE-----