exploit the possibilities

Ubuntu Security Notice USN-4916-2

Ubuntu Security Notice USN-4916-2
Posted Apr 22, 2021
Authored by Ubuntu | Site security.ubuntu.com

Ubuntu Security Notice 4916-2 - USN-4916-1 fixed vulnerabilities in the Linux kernel. Unfortunately, the fix for CVE-2021-3493 introduced a memory leak in some situations. This update fixes the problem. It was discovered that the overlayfs implementation in the Linux kernel did not properly validate the application of file system capabilities with respect to user namespaces. A local attacker could use this to gain elevated privileges. Various other issues were also addressed.

tags | advisory, kernel, local, vulnerability, memory leak
systems | linux, ubuntu
advisories | CVE-2021-29154, CVE-2021-3493
MD5 | 463f8608bb8c56e58878d9bf6dca9de5

Ubuntu Security Notice USN-4916-2

Change Mirror Download
==========================================================================
Ubuntu Security Notice USN-4916-2
April 21, 2021

linux, linux-aws, linux-gke-5.3, linux-hwe, linux-kvm, linux-lts-xenial,
linux-oem-5.6, linux-raspi2-5.3, linux-snapdragon regression
==========================================================================

A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 20.04 LTS
- Ubuntu 18.04 LTS
- Ubuntu 16.04 LTS
- Ubuntu 14.04 ESM

Summary:

USN-4916-1 introduced a regression in the Linux kernel.

Software Description:
- linux-oem-5.6: Linux kernel for OEM systems
- linux-gke-5.3: Linux kernel for Google Container Engine (GKE) systems
- linux-hwe: Linux hardware enablement (HWE) kernel
- linux-raspi2-5.3: Linux kernel for Raspberry Pi (V8) systems
- linux: Linux kernel
- linux-aws: Linux kernel for Amazon Web Services (AWS) systems
- linux-kvm: Linux kernel for cloud environments
- linux-snapdragon: Linux kernel for Qualcomm Snapdragon processors
- linux-lts-xenial: Linux hardware enablement kernel from Xenial for Trusty

Details:

USN-4916-1 fixed vulnerabilities in the Linux kernel. Unfortunately,
the fix for CVE-2021-3493 introduced a memory leak in some situations.
This update fixes the problem.

We apologize for the inconvenience.

Original advisory details:

It was discovered that the overlayfs implementation in the Linux kernel did
not properly validate the application of file system capabilities with
respect to user namespaces. A local attacker could use this to gain
elevated privileges. (CVE-2021-3493)

Piotr Krysiuk discovered that the BPF JIT compiler for x86 in the Linux
kernel did not properly validate computation of branch displacements in
some situations. A local attacker could use this to cause a denial of
service (system crash) or possibly execute arbitrary code. (CVE-2021-29154)

Update instructions:

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 20.04 LTS:
linux-image-5.6.0-1055-oem 5.6.0-1055.59
linux-image-oem-20.04 5.6.0.1055.51

Ubuntu 18.04 LTS:
linux-image-5.3.0-1040-raspi2 5.3.0-1040.42
linux-image-5.3.0-1043-gke 5.3.0-1043.46
linux-image-5.3.0-74-generic 5.3.0-74.70
linux-image-5.3.0-74-lowlatency 5.3.0-74.70
linux-image-gke-5.3 5.3.0.1043.26
linux-image-gkeop-5.3 5.3.0.74.131
linux-image-raspi2-hwe-18.04 5.3.0.1040.29

Ubuntu 16.04 LTS:
linux-image-4.4.0-1093-kvm 4.4.0-1093.102
linux-image-4.4.0-1128-aws 4.4.0-1128.142
linux-image-4.4.0-1156-snapdragon 4.4.0-1156.166
linux-image-4.4.0-210-generic 4.4.0-210.242
linux-image-4.4.0-210-generic-lpae 4.4.0-210.242
linux-image-4.4.0-210-lowlatency 4.4.0-210.242
linux-image-4.4.0-210-powerpc-e500mc 4.4.0-210.242
linux-image-4.4.0-210-powerpc-smp 4.4.0-210.242
linux-image-4.4.0-210-powerpc64-emb 4.4.0-210.242
linux-image-4.4.0-210-powerpc64-smp 4.4.0-210.242
linux-image-aws 4.4.0.1128.133
linux-image-generic 4.4.0.210.216
linux-image-generic-lpae 4.4.0.210.216
linux-image-kvm 4.4.0.1093.91
linux-image-lowlatency 4.4.0.210.216
linux-image-powerpc-e500mc 4.4.0.210.216
linux-image-powerpc-smp 4.4.0.210.216
linux-image-powerpc64-emb 4.4.0.210.216
linux-image-powerpc64-smp 4.4.0.210.216
linux-image-snapdragon 4.4.0.1156.148
linux-image-virtual 4.4.0.210.216

Ubuntu 14.04 ESM:
linux-image-4.4.0-1092-aws 4.4.0-1092.96
linux-image-4.4.0-210-generic 4.4.0-210.242~14.04.1
linux-image-4.4.0-210-generic-lpae 4.4.0-210.242~14.04.1
linux-image-4.4.0-210-lowlatency 4.4.0-210.242~14.04.1
linux-image-4.4.0-210-powerpc-e500mc 4.4.0-210.242~14.04.1
linux-image-4.4.0-210-powerpc-smp 4.4.0-210.242~14.04.1
linux-image-4.4.0-210-powerpc64-emb 4.4.0-210.242~14.04.1
linux-image-4.4.0-210-powerpc64-smp 4.4.0-210.242~14.04.1
linux-image-aws 4.4.0.1092.89
linux-image-generic-lpae-lts-xenial 4.4.0.210.183
linux-image-generic-lts-xenial 4.4.0.210.183
linux-image-lowlatency-lts-xenial 4.4.0.210.183
linux-image-powerpc-e500mc-lts-xenial 4.4.0.210.183
linux-image-powerpc-smp-lts-xenial 4.4.0.210.183
linux-image-powerpc64-emb-lts-xenial 4.4.0.210.183
linux-image-powerpc64-smp-lts-xenial 4.4.0.210.183
linux-image-virtual-lts-xenial 4.4.0.210.183

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:
https://ubuntu.com/security/notices/USN-4916-2
https://ubuntu.com/security/notices/USN-4916-1
https://launchpad.net/bugs/1924611

Package Information:
https://launchpad.net/ubuntu/+source/linux-oem-5.6/5.6.0-1055.59
https://launchpad.net/ubuntu/+source/linux-gke-5.3/5.3.0-1043.46
https://launchpad.net/ubuntu/+source/linux-hwe/5.3.0-74.70
https://launchpad.net/ubuntu/+source/linux-raspi2-5.3/5.3.0-1040.42
https://launchpad.net/ubuntu/+source/linux/4.4.0-210.242
https://launchpad.net/ubuntu/+source/linux-aws/4.4.0-1128.142
https://launchpad.net/ubuntu/+source/linux-kvm/4.4.0-1093.102
https://launchpad.net/ubuntu/+source/linux-snapdragon/4.4.0-1156.166

Login or Register to add favorites

File Archive:

May 2021

  • Su
  • Mo
  • Tu
  • We
  • Th
  • Fr
  • Sa
  • 1
    May 1st
    1 Files
  • 2
    May 2nd
    4 Files
  • 3
    May 3rd
    26 Files
  • 4
    May 4th
    17 Files
  • 5
    May 5th
    3 Files
  • 6
    May 6th
    32 Files
  • 7
    May 7th
    11 Files
  • 8
    May 8th
    2 Files
  • 9
    May 9th
    2 Files
  • 10
    May 10th
    13 Files
  • 11
    May 11th
    17 Files
  • 12
    May 12th
    22 Files
  • 13
    May 13th
    11 Files
  • 14
    May 14th
    0 Files
  • 15
    May 15th
    0 Files
  • 16
    May 16th
    0 Files
  • 17
    May 17th
    0 Files
  • 18
    May 18th
    0 Files
  • 19
    May 19th
    0 Files
  • 20
    May 20th
    0 Files
  • 21
    May 21st
    0 Files
  • 22
    May 22nd
    0 Files
  • 23
    May 23rd
    0 Files
  • 24
    May 24th
    0 Files
  • 25
    May 25th
    0 Files
  • 26
    May 26th
    0 Files
  • 27
    May 27th
    0 Files
  • 28
    May 28th
    0 Files
  • 29
    May 29th
    0 Files
  • 30
    May 30th
    0 Files
  • 31
    May 31st
    0 Files

Top Authors In Last 30 Days

File Tags

Systems

packet storm

© 2020 Packet Storm. All rights reserved.

Services
Security Services
Hosting By
Rokasec
close