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AUSCERT External Security Bulletin Redistribution
ESB-2021.0070
USN-4680-1: Linux kernel vulnerabilities
7 January 2021
===========================================================================
AusCERT Security Bulletin Summary
---------------------------------
Product: kernel
Publisher: Ubuntu
Operating System: Ubuntu
Impact/Access: Execute Arbitrary Code/Commands -- Existing Account
Access Privileged Data -- Existing Account
Denial of Service -- Existing Account
Unauthorised Access -- Existing Account
Reduced Security -- Existing Account
Resolution: Patch/Upgrade
CVE Names: CVE-2020-28974 CVE-2020-27777 CVE-2020-27675
CVE-2020-25705 CVE-2020-25668 CVE-2020-25656
CVE-2020-10135 CVE-2020-0423 CVE-2019-19770
Reference: ESB-2020.4377
ESB-2020.4375
ESB-2020.4181
Original Bulletin:
https://ubuntu.com/security/notices/USN-4680-1
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USN-4680-1: Linux kernel vulnerabilities
06 January 2021
Several security issues were fixed in the Linux kernel.
Releases
o Ubuntu 18.04 LTS
o Ubuntu 16.04 LTS
o Ubuntu 14.04 ESM
Packages
o linux - Linux kernel
o linux-aws - Linux kernel for Amazon Web Services (AWS) systems
o linux-aws-hwe - Linux kernel for Amazon Web Services (AWS-HWE) systems
o linux-azure - Linux kernel for Microsoft Azure Cloud systems
o linux-azure-4.15 - Linux kernel for Microsoft Azure Cloud systems
o linux-gcp - Linux kernel for Google Cloud Platform (GCP) systems
o linux-gcp-4.15 - Linux kernel for Google Cloud Platform (GCP) systems
o linux-gke-4.15 - Linux kernel for Google Container Engine (GKE) systems
o linux-hwe - Linux hardware enablement (HWE) kernel
o linux-kvm - Linux kernel for cloud environments
o linux-oracle - Linux kernel for Oracle Cloud systems
o linux-raspi2 - Linux kernel for Raspberry Pi (V8) systems
o linux-snapdragon - Linux kernel for Qualcomm Snapdragon processors
Details
It was discovered that debugfs in the Linux kernel as used by blktrace
contained a use-after-free in some situations. A privileged local attacker
could possibly use this to cause a denial of service (system crash).
(CVE-2019-19770)
It was discovered that a race condition existed in the binder IPC
implementation in the Linux kernel, 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-2020-0423)
Daniele Antonioli, Nils Ole Tippenhauer, and Kasper Rasmussen discovered
that legacy pairing and secure-connections pairing authentication in the
Bluetooth protocol could allow an unauthenticated user to complete
authentication without pairing credentials via adjacent access. A
physically proximate attacker could use this to impersonate a previously
paired Bluetooth device. (CVE-2020-10135)
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)
Keyu Man discovered that the ICMP global rate limiter in the Linux kernel
could be used to assist in scanning open UDP ports. A remote attacker could
use to facilitate attacks on UDP based services that depend on source port
randomization. (CVE-2020-25705)
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)
Update instructions
The problem can be corrected by updating your system to the following package
versions:
Ubuntu 18.04
o linux-image-4.15.0-1062-oracle - 4.15.0-1062.68
o linux-image-4.15.0-1077-gke - 4.15.0-1077.82
o linux-image-4.15.0-1077-raspi2 - 4.15.0-1077.82
o linux-image-4.15.0-1082-kvm - 4.15.0-1082.84
o linux-image-4.15.0-1091-aws - 4.15.0-1091.96
o linux-image-4.15.0-1091-gcp - 4.15.0-1091.104
o linux-image-4.15.0-1094-snapdragon - 4.15.0-1094.103
o linux-image-4.15.0-1103-azure - 4.15.0-1103.114
o linux-image-4.15.0-129-generic - 4.15.0-129.132
o linux-image-4.15.0-129-generic-lpae - 4.15.0-129.132
o linux-image-4.15.0-129-lowlatency - 4.15.0-129.132
o linux-image-aws-lts-18.04 - 4.15.0.1091.93
o linux-image-azure-lts-18.04 - 4.15.0.1103.76
o linux-image-gcp-lts-18.04 - 4.15.0.1091.109
o linux-image-generic - 4.15.0.129.116
o linux-image-generic-lpae - 4.15.0.129.116
o linux-image-gke - 4.15.0.1077.81
o linux-image-gke-4.15 - 4.15.0.1077.81
o linux-image-kvm - 4.15.0.1082.78
o linux-image-lowlatency - 4.15.0.129.116
o linux-image-oracle-lts-18.04 - 4.15.0.1062.72
o linux-image-powerpc-e500mc - 4.15.0.129.116
o linux-image-powerpc-smp - 4.15.0.129.116
o linux-image-powerpc64-emb - 4.15.0.129.116
o linux-image-powerpc64-smp - 4.15.0.129.116
o linux-image-raspi2 - 4.15.0.1077.74
o linux-image-snapdragon - 4.15.0.1094.97
o linux-image-virtual - 4.15.0.129.116
Ubuntu 16.04
o linux-image-4.15.0-1062-oracle - 4.15.0-1062.68~16.04.1
o linux-image-4.15.0-1091-aws - 4.15.0-1091.96~16.04.1
o linux-image-4.15.0-1091-gcp - 4.15.0-1091.104~16.04.1
o linux-image-4.15.0-1103-azure - 4.15.0-1103.114~16.04.1
o linux-image-4.15.0-129-generic - 4.15.0-129.132~16.04.1
o linux-image-4.15.0-129-generic-lpae - 4.15.0-129.132~16.04.1
o linux-image-4.15.0-129-lowlatency - 4.15.0-129.132~16.04.1
o linux-image-aws-hwe - 4.15.0.1091.85
o linux-image-azure - 4.15.0.1103.96
o linux-image-gcp - 4.15.0.1091.92
o linux-image-generic-hwe-16.04 - 4.15.0.129.128
o linux-image-generic-lpae-hwe-16.04 - 4.15.0.129.128
o linux-image-gke - 4.15.0.1091.92
o linux-image-lowlatency-hwe-16.04 - 4.15.0.129.128
o linux-image-oem - 4.15.0.129.128
o linux-image-oracle - 4.15.0.1062.51
o linux-image-virtual-hwe-16.04 - 4.15.0.129.128
Ubuntu 14.04
o linux-image-4.15.0-1103-azure - 4.15.0-1103.114~14.04.1
o linux-image-azure - 4.15.0.1103.78
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-2020-0423
o CVE-2020-28974
o CVE-2020-25656
o CVE-2020-10135
o CVE-2020-27675
o CVE-2020-27777
o CVE-2020-25705
o CVE-2019-19770
o CVE-2020-25668
Related notices
o USN-4681-1 : linux-kvm, linux-image-powerpc64-emb-lts-xenial,
linux-image-4.4.0-1143-raspi2, linux-image-kvm, linux-image-powerpc64-smp,
linux, linux-image-powerpc-smp-lts-xenial, linux-image-generic-lts-xenial,
linux-image-raspi2, linux-image-4.4.0-198-powerpc-smp,
linux-image-4.4.0-198-lowlatency, linux-image-lowlatency,
linux-image-lowlatency-lts-xenial, linux-image-4.4.0-1119-aws,
linux-image-aws, linux-lts-xenial, linux-aws, linux-image-virtual,
linux-image-4.4.0-198-powerpc64-emb, linux-image-4.4.0-198-generic,
linux-image-4.4.0-198-powerpc-e500mc, linux-image-snapdragon,
linux-image-4.4.0-198-generic-lpae, linux-image-powerpc64-emb,
linux-image-4.4.0-1085-kvm, linux-image-powerpc64-smp-lts-xenial,
linux-image-generic-lpae-lts-xenial, linux-image-generic-lpae,
linux-image-powerpc-smp, linux-raspi2, linux-image-4.4.0-198-powerpc64-smp,
linux-image-powerpc-e500mc, linux-image-powerpc-e500mc-lts-xenial,
linux-image-4.4.0-1147-snapdragon, linux-snapdragon,
linux-image-virtual-lts-xenial, linux-image-4.4.0-1083-aws,
linux-image-generic
o USN-4657-1 : linux-image-4.4.0-1142-raspi2, linux-kvm,
linux-image-powerpc64-emb-lts-xenial, linux-image-kvm,
linux-image-powerpc64-smp, linux, linux-image-powerpc-smp-lts-xenial,
linux-image-4.4.0-197-powerpc64-emb, linux-image-4.4.0-197-powerpc-smp,
linux-image-generic-lts-xenial, linux-image-raspi2, linux-image-lowlatency,
linux-image-4.4.0-1146-snapdragon, linux-image-lowlatency-lts-xenial,
linux-image-4.4.0-197-powerpc64-smp, linux-image-aws, linux-lts-xenial,
linux-aws, linux-image-virtual, linux-image-4.4.0-197-generic-lpae,
linux-image-snapdragon, linux-image-powerpc64-emb,
linux-image-4.4.0-1084-kvm, linux-image-4.4.0-197-powerpc-e500mc,
linux-image-4.4.0-1118-aws, linux-image-powerpc64-smp-lts-xenial,
linux-image-generic-lpae-lts-xenial, linux-image-generic-lpae,
linux-image-4.4.0-197-generic, linux-image-powerpc-smp, linux-raspi2,
linux-image-powerpc-e500mc, linux-image-powerpc-e500mc-lts-xenial,
linux-snapdragon, linux-image-virtual-lts-xenial,
linux-image-4.4.0-197-lowlatency, linux-image-4.4.0-1082-aws,
linux-image-generic
o USN-4679-1 : linux-image-5.4.0-1034-aws, linux-kvm,
linux-image-5.4.0-1035-azure, linux-image-kvm, linux-aws-5.4,
linux-image-oracle, linux-image-5.4.0-1033-gcp, linux, linux-raspi,
linux-gcp-5.4, linux-raspi-5.4, linux-image-lowlatency-hwe-18.04,
linux-image-raspi2, linux-image-gcp, linux-image-5.4.0-1026-raspi,
linux-image-lowlatency, linux-oracle, linux-image-generic-lpae-hwe-18.04,
linux-gke-5.4, linux-image-aws, linux-oracle-5.4, linux-azure, linux-aws,
linux-image-gke-5.4, linux-image-raspi, linux-image-virtual,
linux-azure-5.4, linux-image-5.4.0-1033-gke, linux-image-raspi-hwe-18.04,
linux-image-snapdragon-hwe-18.04, linux-image-oem-osp1,
linux-image-5.4.0-1031-kvm, linux-image-generic-lpae,
linux-image-5.4.0-59-generic, linux-image-generic-hwe-18.04, linux-hwe-5.4,
linux-image-5.4.0-59-generic-lpae, linux-image-5.4.0-59-lowlatency,
linux-image-virtual-hwe-18.04, linux-gcp, linux-image-oem,
linux-image-azure, linux-image-generic, linux-image-5.4.0-1034-oracle
o USN-4659-1 : linux-image-5.8.0-1008-raspi, linux-kvm, linux-image-kvm,
linux-image-5.8.0-1011-oracle, linux-image-oracle, linux, linux-raspi,
linux-image-5.8.0-31-generic, linux-image-gcp, linux-image-5.8.0-1012-gcp,
linux-image-lowlatency, linux-oracle, linux-image-aws, linux-azure,
linux-aws, linux-image-virtual, linux-image-raspi,
linux-image-5.8.0-31-generic-lpae, linux-image-generic-64k,
linux-image-gke, linux-image-5.8.0-31-generic-64k,
linux-image-5.8.0-1011-kvm, linux-image-oem-20.04,
linux-image-generic-lpae, linux-image-5.8.0-1013-azure,
linux-image-raspi-nolpae, linux-gcp, linux-image-5.8.0-1014-aws,
linux-image-azure, linux-image-5.8.0-31-lowlatency, linux-image-generic,
linux-image-5.8.0-1008-raspi-nolpae
o USN-4658-1 : linux-image-5.4.0-56-generic, linux-image-5.4.0-56-lowlatency,
linux-kvm, linux-image-5.4.0-1030-oracle, linux-image-kvm, linux-aws-5.4,
linux-image-oracle, linux, linux-raspi, linux-image-5.4.0-1028-kvm,
linux-gcp-5.4, linux-image-5.4.0-56-generic-lpae,
linux-image-5.4.0-1032-azure, linux-image-lowlatency-hwe-20.04,
linux-raspi-5.4, linux-image-lowlatency-hwe-18.04, linux-image-raspi2,
linux-image-gcp, linux-image-lowlatency, linux-oracle,
linux-image-generic-lpae-hwe-18.04, linux-image-aws, linux-oracle-5.4,
linux-azure, linux-aws, linux-image-virtual, linux-image-raspi,
linux-azure-5.4, linux-image-raspi-hwe-18.04,
linux-image-snapdragon-hwe-18.04, linux-image-gke,
linux-image-5.4.0-1023-raspi, linux-image-oem-osp1,
linux-image-generic-lpae, linux-image-5.4.0-1030-aws,
linux-image-generic-hwe-18.04, linux-image-generic-lpae-hwe-20.04,
linux-image-generic-hwe-20.04, linux-hwe-5.4,
linux-image-virtual-hwe-18.04, linux-image-5.4.0-1030-gcp,
linux-image-virtual-hwe-20.04, linux-gcp, linux-image-oem,
linux-image-azure, linux-image-generic
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