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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2020.3008.2 USN-4483-1: Linux kernel vulnerabilities 4 September 2020 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: kernel Publisher: Ubuntu Operating System: Ubuntu Impact/Access: Root Compromise -- Existing Account Access Privileged Data -- Existing Account Denial of Service -- Existing Account Reduced Security -- Existing Account Resolution: Patch/Upgrade CVE Names: CVE-2020-24394 CVE-2020-15393 CVE-2020-14356 CVE-2020-13974 CVE-2020-12771 CVE-2020-12656 CVE-2020-12655 CVE-2020-10781 CVE-2020-10768 CVE-2020-10767 CVE-2020-10766 CVE-2020-10757 CVE-2019-20810 Reference: ESB-2020.3004 ESB-2020.2907 ESB-2020.2864.2 ESB-2020.2842 Original Bulletin: https://usn.ubuntu.com/4483-1/ Revision History: September 4 2020: Vendor added new kernel version details September 2 2020: Initial Release - --------------------------BEGIN INCLUDED TEXT-------------------- USN-4483-1: Linux kernel vulnerabilities 03 September 2020 Several security issues were fixed in the Linux kernel. Releases 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-hwe-5.4 - Linux hardware enablement (HWE) kernel o linux-kvm - Linux kernel for cloud environments 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 Details Chuhong Yuan discovered that go7007 USB audio device driver in the Linux kernel did not properly deallocate memory in some failure conditions. A physically proximate attacker could use this to cause a denial of service (memory exhaustion). (CVE-2019-20810) Fan Yang discovered that the mremap implementation in the Linux kernel did not properly handle DAX Huge Pages. A local attacker with access to DAX storage could use this to gain administrative privileges. (CVE-2020-10757) It was discovered that the Linux kernel did not correctly apply Speculative Store Bypass Disable (SSBD) mitigations in certain situations. A local attacker could possibly use this to expose sensitive information. (CVE-2020-10766) It was discovered that the Linux kernel did not correctly apply Indirect Branch Predictor Barrier (IBPB) mitigations in certain situations. A local attacker could possibly use this to expose sensitive information. (CVE-2020-10767) It was discovered that the Linux kernel could incorrectly enable Indirect Branch Speculation after it has been disabled for a process via a prctl() call. A local attacker could possibly use this to expose sensitive information. (CVE-2020-10768) Luca Bruno discovered that the zram module in the Linux kernel did not properly restrict unprivileged users from accessing the hot_add sysfs file. A local attacker could use this to cause a denial of service (memory exhaustion). (CVE-2020-10781) It was discovered that the XFS file system implementation in the Linux kernel did not properly validate meta data in some circumstances. An attacker could use this to construct a malicious XFS image that, when mounted, could cause a denial of service. (CVE-2020-12655) It was discovered that the bcache subsystem in the Linux kernel did not properly release a lock in some error conditions. A local attacker could possibly use this to cause a denial of service. (CVE-2020-12771) It was discovered that the Virtual Terminal keyboard driver in the Linux kernel contained an integer overflow. A local attacker could possibly use this to have an unspecified impact. (CVE-2020-13974) It was discovered that the cgroup v2 subsystem in the Linux kernel did not properly perform reference counting in some situations, leading to a NULL pointer dereference. A local attacker could use this to cause a denial of service or possibly gain administrative privileges. (CVE-2020-14356) Kyungtae Kim discovered that the USB testing driver in the Linux kernel did not properly deallocate memory on disconnect events. A physically proximate attacker could use this to cause a denial of service (memory exhaustion). (CVE-2020-15393) It was discovered that the NFS server implementation in the Linux kernel did not properly honor umask settings when setting permissions while creating file system objects if the underlying file system did not support ACLs. An attacker could possibly use this to expose sensitive information or violate system integrity. (CVE-2020-24394) It was discovered that the Kerberos SUNRPC GSS implementation in the Linux kernel did not properly deallocate memory on module unload. A local privileged attacker could possibly use this to cause a denial of service (memory exhaustion). (CVE-2020-12656) Update instructions The problem can be corrected by updating your system to the following package versions: Ubuntu 20.04 o linux-image-5.4.0-1016-raspi - 5.4.0-1016.17 o linux-image-5.4.0-1022-aws - 5.4.0-1022.22 o linux-image-5.4.0-1022-gcp - 5.4.0-1022.22 o linux-image-5.4.0-1022-oracle - 5.4.0-1022.22 o linux-image-5.4.0-1023-azure - 5.4.0-1023.23 o linux-image-5.4.0-45-generic - 5.4.0-45.49 o linux-image-5.4.0-45-generic-lpae - 5.4.0-45.49 o linux-image-5.4.0-45-lowlatency - 5.4.0-45.49 o linux-image-aws - 5.4.0.1022.23 o linux-image-azure - 5.4.0.1023.22 o linux-image-gcp - 5.4.0.1022.20 o linux-image-generic - 5.4.0.45.49 o linux-image-generic-lpae - 5.4.0.45.49 o linux-image-gke - 5.4.0.1022.20 o linux-image-kvm - 5.4.0.1021.20 o linux-image-lowlatency - 5.4.0.45.49 o linux-image-oem - 5.4.0.45.49 o linux-image-oem-osp1 - 5.4.0.45.49 o linux-image-oracle - 5.4.0.1022.20 o linux-image-raspi - 5.4.0.1016.51 o linux-image-raspi2 - 5.4.0.1016.51 o linux-image-virtual - 5.4.0.45.49 Ubuntu 18.04 o linux-image-5.4.0-1016-raspi - 5.4.0-1016.17~18.04.1 o linux-image-5.4.0-1022-aws - 5.4.0-1022.22~18.04.1 o linux-image-5.4.0-1022-gcp - 5.4.0-1022.22~18.04.1 o linux-image-5.4.0-1022-oracle - 5.4.0-1022.22~18.04.1 o linux-image-5.4.0-1023-azure - 5.4.0-1023.23~18.04.1 o linux-image-5.4.0-45-generic - 5.4.0-45.49~18.04.2 o linux-image-5.4.0-45-generic-lpae - 5.4.0-45.49~18.04.2 o linux-image-5.4.0-45-lowlatency - 5.4.0-45.49~18.04.2 o linux-image-aws-edge - 5.4.0.1022.8 o linux-image-azure - 5.4.0.1023.7 o linux-image-gcp - 5.4.0.1022.9 o linux-image-generic-hwe-18.04 - 5.4.0.45.49~18.04.38 o linux-image-generic-lpae-hwe-18.04 - 5.4.0.45.49~18.04.38 o linux-image-gke-5.4 - 5.4.0.1022.9 o linux-image-gkeop-5.4 - 5.4.0.45.49~18.04.38 o linux-image-lowlatency-hwe-18.04 - 5.4.0.45.49~18.04.38 o linux-image-oracle - 5.4.0.1022.7 o linux-image-raspi-hwe-18.04 - 5.4.0.1016.20 o linux-image-snapdragon-hwe-18.04 - 5.4.0.45.49~18.04.38 o linux-image-virtual-hwe-18.04 - 5.4.0.45.49~18.04.38 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-2019-20810 o CVE-2020-10757 o CVE-2020-10766 o CVE-2020-10767 o CVE-2020-10768 o CVE-2020-10781 o CVE-2020-12655 o CVE-2020-12656 o CVE-2020-12771 o CVE-2020-13974 o CVE-2020-14356 o CVE-2020-15393 o CVE-2020-24394 - --------------------------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. 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On call after hours for member emergencies only. =========================================================================== -----BEGIN PGP SIGNATURE----- Comment: http://www.auscert.org.au/render.html?it=1967 iQIVAwUBX1GvCuNLKJtyKPYoAQh0dBAAkNBt7aGRNoUwtJp3BmNhXmqfm79Zm1AE PMHfeMT3Nwk0eDaAkLPbM5bjlpg6vSYwrfbIFRrMSidgXwK3YfLiHlU8T8duM2Qh yhb3ULSq7u5bmi5Te0dASU4ohVWSawS9WcPmQnGbLwj0KiK0hOtrmceMtMM0rqUt Dyjab0Eo9Mz4g4Kjyb1eVfhAEkROpM0rjHfsVeJmfOkjfBN5uZsXeKzYCLYp0cYY o89XF0kJJcTbxosl5nOLb4VhgF7FAc7vNBiyd7YmUYZ+6+MQum4ruG5aJzANekSL xTWQEjWW7pIK2UxgWwaYrUsdDe0yg8dCFKNG1mwxTsOT7IoQaLonvlxcTed4Miy5 l6Eq0HkA+wl3BF3ntVzUztOWBqpCTZYToM+3kED1G7AA3EtsVhVO+/bHd5ootiKe kay+NABzDT6/apE/2UkIc/FB/wp6LTOD4NqxC+8V2uksio3mTA6QBlhGqOHhZYhO OVnH3YCyvWl8oTC2Di/Fwr0vFFHXT/aJar8KQcc+Q+h1Uw7LD/gUkbsdH9DbNKxA 11Jr3TiCXieTTZpa6g9sScKE/nTYRoEHxwprWsvUNWAUpBpmWPr0ha4VK6rPOQ93 pZYiQqZmTKscwotKy79bgbc2PimIYp8H4UvMyqBWQdXyOTfxdLYRHVayVZamMilK MWdeH5CJVSs= =B37a -----END PGP SIGNATURE-----