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AUSCERT External Security Bulletin Redistribution
ESB-2021.1002
USN-4887-1: Linux kernel vulnerabilities
24 March 2021
===========================================================================
AusCERT Security Bulletin Summary
---------------------------------
Product: kernel
Publisher: Ubuntu
Operating System: Ubuntu
Impact/Access: Execute Arbitrary Code/Commands -- Existing Account
Denial of Service -- Existing Account
Access Confidential Data -- Existing Account
Resolution: Patch/Upgrade
CVE Names: CVE-2021-27365 CVE-2021-27364 CVE-2021-27363
CVE-2021-3444 CVE-2020-27171 CVE-2020-27170
Reference: ESB-2021.0981
ESB-2021.0837
Original Bulletin:
https://ubuntu.com/security/notices/USN-4887-1
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USN-4887-1: Linux kernel vulnerabilities
23 March 2021
Several security issues were fixed in the Linux kernel.
Releases
o Ubuntu 20.10
o Ubuntu 20.04 LTS
o Ubuntu 18.04 LTS
Packages
o linux - Linux kernel
o linux-aws - Linux kernel for Amazon Web Services (AWS) systems
o linux-aws-5.4 - Linux kernel for Amazon Web Services (AWS) systems
o linux-azure - Linux kernel for Microsoft Azure Cloud systems
o linux-azure-5.4 - Linux kernel for Microsoft Azure cloud systems
o linux-gcp - Linux kernel for Google Cloud Platform (GCP) systems
o linux-gcp-5.4 - Linux kernel for Google Cloud Platform (GCP) systems
o linux-gke-5.3 - Linux kernel for Google Container Engine (GKE) systems
o linux-gke-5.4 - Linux kernel for Google Container Engine (GKE) systems
o linux-gkeop - Linux kernel for Google Container Engine (GKE) systems
o linux-gkeop-5.4 - Linux kernel for Google Container Engine (GKE) systems
o linux-hwe - Linux hardware enablement (HWE) kernel
o linux-hwe-5.4 - Linux hardware enablement (HWE) kernel
o linux-hwe-5.8 - Linux hardware enablement (HWE) kernel
o linux-kvm - Linux kernel for cloud environments
o linux-oem-5.10 - Linux kernel for OEM systems
o linux-oem-5.6 - Linux kernel for OEM systems
o linux-oracle - Linux kernel for Oracle Cloud systems
o linux-oracle-5.4 - Linux kernel for Oracle Cloud systems
o linux-raspi - Linux kernel for Raspberry Pi (V8) systems
o linux-raspi-5.4 - Linux kernel for Raspberry Pi (V8) systems
o linux-raspi2-5.3 - Linux kernel for Raspberry Pi (V8) systems
Details
De4dCr0w of 360 Alpha Lab discovered that the BPF verifier in the Linux
kernel did not properly handle mod32 destination register truncation when
the source register was known to be 0. A local attacker could use this to
expose sensitive information (kernel memory) or possibly execute arbitrary
code. ( CVE-2021-3444 )
Adam Nichols discovered that heap overflows existed in the iSCSI subsystem
in the Linux kernel. A local attacker could use this to cause a denial of
service (system crash) or possibly execute arbitrary code. ( CVE-2021-27365 )
Piotr Krysiuk discovered that the BPF subsystem in the Linux kernel did not
properly compute a speculative execution limit on pointer arithmetic in
some situations. A local attacker could use this to expose sensitive
information (kernel memory). ( CVE-2020-27171 )
Piotr Krysiuk discovered that the BPF subsystem in the Linux kernel did not
properly apply speculative execution limits on some pointer types. A local
attacker could use this to expose sensitive information (kernel memory).
( CVE-2020-27170 )
Adam Nichols discovered that the iSCSI subsystem in the Linux kernel did
not properly restrict access to iSCSI transport handles. A local attacker
could use this to cause a denial of service or expose sensitive information
(kernel pointer addresses). ( CVE-2021-27363 )
Adam Nichols discovered that an out-of-bounds read existed in the iSCSI
subsystem in the Linux kernel. A local attacker could use this to cause a
denial of service (system crash) or expose sensitive information (kernel
memory). ( CVE-2021-27364 )
Update instructions
The problem can be corrected by updating your system to the following package
versions:
Ubuntu 20.10
o linux-image-5.8.0-1022-kvm - 5.8.0-1022.24
o linux-image-oracle - 5.8.0.1024.23
o linux-image-5.8.0-1019-raspi - 5.8.0-1019.22
o linux-image-azure - 5.8.0.1026.26
o linux-image-raspi-nolpae - 5.8.0.1019.22
o linux-image-5.8.0-1024-oracle - 5.8.0-1024.25
o linux-image-oem-20.04 - 5.8.0.48.53
o linux-image-virtual - 5.8.0.48.53
o linux-image-5.8.0-1026-gcp - 5.8.0-1026.27
o linux-image-raspi - 5.8.0.1019.22
o linux-image-5.8.0-48-lowlatency - 5.8.0-48.54
o linux-image-gke - 5.8.0.1026.26
o linux-image-generic-64k - 5.8.0.48.53
o linux-image-generic - 5.8.0.48.53
o linux-image-5.8.0-1026-azure - 5.8.0-1026.28
o linux-image-5.8.0-1027-aws - 5.8.0-1027.29
o linux-image-aws - 5.8.0.1027.29
o linux-image-kvm - 5.8.0.1022.24
o linux-image-5.8.0-48-generic-64k - 5.8.0-48.54
o linux-image-5.8.0-48-generic - 5.8.0-48.54
o linux-image-5.8.0-1019-raspi-nolpae - 5.8.0-1019.22
o linux-image-generic-lpae - 5.8.0.48.53
o linux-image-gcp - 5.8.0.1026.26
o linux-image-5.8.0-48-generic-lpae - 5.8.0-48.54
o linux-image-lowlatency - 5.8.0.48.53
Ubuntu 20.04
o linux-image-virtual - 5.4.0.70.73
o linux-image-5.4.0-70-generic-lpae - 5.4.0-70.78
o linux-image-virtual-hwe-20.04 - 5.8.0.48.54~20.04.32
o linux-image-gcp - 5.4.0.1040.49
o linux-image-gkeop-5.4 - 5.4.0.1012.15
o linux-image-5.10.0-1019-oem - 5.10.0-1019.20
o linux-image-5.6.0-1052-oem - 5.6.0-1052.56
o linux-image-oem-osp1 - 5.4.0.70.73
o linux-image-generic-hwe-20.04 - 5.8.0.48.54~20.04.32
o linux-image-oracle - 5.4.0.1041.38
o linux-image-azure - 5.4.0.1043.41
o linux-image-generic-lpae-hwe-20.04 - 5.8.0.48.54~20.04.32
o linux-image-5.4.0-1036-kvm - 5.4.0-1036.37
o linux-image-oem-20.04 - 5.6.0.1052.48
o linux-image-gkeop - 5.4.0.1012.15
o linux-image-5.4.0-1041-oracle - 5.4.0-1041.44
o linux-image-oem-20.04b - 5.10.0.1019.20
o linux-image-5.4.0-70-lowlatency - 5.4.0-70.78
o linux-image-raspi - 5.4.0.1032.67
o linux-image-5.8.0-48-lowlatency - 5.8.0-48.54~20.04.1
o linux-image-5.4.0-1041-aws - 5.4.0-1041.43
o linux-image-5.4.0-1032-raspi - 5.4.0-1032.35
o linux-image-generic - 5.4.0.70.73
o linux-image-generic-64k-hwe-20.04 - 5.8.0.48.54~20.04.32
o linux-image-oem - 5.4.0.70.73
o linux-image-aws - 5.4.0.1041.42
o linux-image-kvm - 5.4.0.1036.34
o linux-image-raspi2 - 5.4.0.1032.67
o linux-image-5.8.0-48-generic-64k - 5.8.0-48.54~20.04.1
o linux-image-5.8.0-48-generic - 5.8.0-48.54~20.04.1
o linux-image-5.4.0-1040-gcp - 5.4.0-1040.43
o linux-image-generic-lpae - 5.4.0.70.73
o linux-image-5.4.0-70-generic - 5.4.0-70.78
o linux-image-5.8.0-48-generic-lpae - 5.8.0-48.54~20.04.1
o linux-image-lowlatency-hwe-20.04 - 5.8.0.48.54~20.04.32
o linux-image-5.4.0-1012-gkeop - 5.4.0-1012.13
o linux-image-lowlatency - 5.4.0.70.73
o linux-image-5.4.0-1043-azure - 5.4.0-1043.45
Ubuntu 18.04
o linux-image-5.4.0-70-generic-lpae - 5.4.0-70.78~18.04.1
o linux-image-gkeop-5.3 - 5.3.0.72.129
o linux-image-gcp - 5.4.0.1040.27
o linux-image-gkeop-5.4 - 5.4.0.1012.13~18.04.13
o linux-image-oem-osp1 - 5.4.0.70.78~18.04.63
o linux-image-oracle - 5.4.0.1041.44~18.04.23
o linux-image-generic-hwe-18.04 - 5.4.0.70.78~18.04.63
o linux-image-azure - 5.4.0.1043.23
o linux-image-snapdragon-hwe-18.04 - 5.4.0.70.78~18.04.63
o linux-image-5.4.0-1039-gke - 5.4.0-1039.41~18.04.1
o linux-image-generic-lpae-hwe-18.04 - 5.4.0.70.78~18.04.63
o linux-image-5.3.0-72-lowlatency - 5.3.0-72.68
o linux-image-5.4.0-70-lowlatency - 5.4.0-70.78~18.04.1
o linux-image-virtual-hwe-18.04 - 5.4.0.70.78~18.04.63
o linux-image-5.4.0-1032-raspi - 5.4.0-1032.35~18.04.1
o linux-image-5.3.0-72-generic - 5.3.0-72.68
o linux-image-lowlatency-hwe-18.04 - 5.4.0.70.78~18.04.63
o linux-image-5.3.0-1038-raspi2 - 5.3.0-1038.40
o linux-image-gke-5.3 - 5.3.0.1041.24
o linux-image-gke-5.4 - 5.4.0.1039.41~18.04.6
o linux-image-oem - 5.4.0.70.78~18.04.63
o linux-image-5.3.0-1041-gke - 5.3.0-1041.44
o linux-image-aws - 5.4.0.1041.24
o linux-image-5.4.0-1041-aws - 5.4.0-1041.43~18.04.1
o linux-image-5.4.0-1040-gcp - 5.4.0-1040.43~18.04.1
o linux-image-raspi-hwe-18.04 - 5.4.0.1032.34
o linux-image-5.4.0-70-generic - 5.4.0-70.78~18.04.1
o linux-image-5.4.0-1041-oracle - 5.4.0-1041.44~18.04.1
o linux-image-5.4.0-1012-gkeop - 5.4.0-1012.13~18.04.1
o linux-image-raspi2-hwe-18.04 - 5.3.0.1038.27
o linux-image-5.4.0-1043-azure - 5.4.0-1043.45~18.04.1
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-2020-27170
o CVE-2021-27364
o CVE-2020-27171
o CVE-2021-27363
o CVE-2021-3444
o CVE-2021-27365
Related notices
o USN-4883-1 : linux-image-4.4.0-206-powerpc64-emb,
linux-image-4.4.0-1152-snapdragon, linux-azure,
linux-image-generic-lpae-hwe-16.04, linux-image-4.15.0-1067-oracle,
linux-image-generic-lpae, linux-image-raspi2, linux-snapdragon, linux,
linux-image-generic-hwe-16.04, linux-hwe, linux-image-lowlatency,
linux-image-4.4.0-1090-kvm, linux-image-aws-hwe, linux-gcp-4.15,
linux-image-4.15.0-1110-azure, linux-image-4.4.0-1088-aws,
linux-image-4.15.0-139-generic, linux-image-aws, linux-image-azure-edge,
linux-gcp, linux-image-aws-lts-18.04, linux-image-4.15.0-1087-kvm,
linux-image-snapdragon, linux-image-4.15.0-1098-snapdragon, linux-aws-hwe,
linux-image-oem, linux-oracle, linux-image-generic,
linux-image-4.15.0-1081-raspi2, linux-image-4.4.0-206-lowlatency,
linux-image-kvm, linux-image-gke, linux-image-powerpc64-emb,
linux-image-oracle, linux-image-virtual, linux-image-gcp,
linux-image-powerpc-smp, linux-kvm, linux-image-azure,
linux-image-azure-lts-18.04, linux-image-oracle-lts-18.04,
linux-image-lowlatency-hwe-16.04, linux-aws, linux-image-gcp-lts-18.04,
linux-raspi2, linux-image-powerpc-e500mc,
linux-image-4.4.0-206-powerpc-smp, linux-image-4.4.0-206-powerpc64-smp,
linux-image-powerpc64-smp, linux-image-4.15.0-1096-aws, linux-azure-4.15,
linux-image-4.15.0-139-lowlatency, linux-image-4.4.0-1124-aws,
linux-image-4.4.0-206-generic-lpae, linux-image-4.4.0-206-generic,
linux-image-virtual-hwe-16.04, linux-image-4.15.0-139-generic-lpae,
linux-image-4.4.0-206-powerpc-e500mc, linux-image-4.15.0-1095-gcp
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