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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2018.3737 Linux kernel (AWS) vulnerabilities 3 December 2018 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: linux-image-4.18.0-1006-aws Publisher: Ubuntu Operating System: Ubuntu Platform: AWS Impact/Access: Root Compromise -- Existing Account Access Privileged Data -- Existing Account Denial of Service -- Existing Account Unauthorised Access -- Existing Account Resolution: Patch/Upgrade CVE Names: CVE-2018-18955 CVE-2018-18653 CVE-2018-18445 CVE-2018-18281 CVE-2018-17972 CVE-2018-6559 Original Bulletin: http://www.ubuntu.com/usn/usn-3832-1 http://www.ubuntu.com/usn/usn-3833-1 Comment: This bulletin contains two (2) Ubuntu security advisories. - --------------------------BEGIN INCLUDED TEXT-------------------- ========================================================================== Ubuntu Security Notice USN-3832-1 November 30, 2018 linux-aws vulnerabilities ========================================================================== A security issue affects these releases of Ubuntu and its derivatives: - - Ubuntu 18.10 Summary: Several security issues were fixed in the Linux kernel. Software Description: - - linux-aws: Linux kernel for Amazon Web Services (AWS) systems Details: Jann Horn discovered that the procfs file system implementation in the Linux kernel did not properly restrict the ability to inspect the kernel stack of an arbitrary task. A local attacker could use this to expose sensitive information. (CVE-2018-17972) Jann Horn discovered that the mremap() system call in the Linux kernel did not properly flush the TLB when completing, potentially leaving access to a physical page after it has been released to the page allocator. A local attacker could use this to cause a denial of service (system crash), expose sensitive information, or possibly execute arbitrary code. (CVE-2018-18281) It was discovered that the BPF verifier in the Linux kernel did not correctly compute numeric bounds in some situations. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2018-18445) Daniel Dadap discovered that the module loading implementation in the Linux kernel did not properly enforce signed module loading when booted with UEFI Secure Boot in some situations. A local privileged attacker could use this to execute untrusted code in the kernel. (CVE-2018-18653) Jann Horn discovered that the Linux kernel mishandles mapping UID or GID ranges inside nested user namespaces in some situations. A local attacker could use this to bypass access controls on resources outside the namespace. (CVE-2018-18955) Philipp Wendler discovered that the overlayfs implementation in the Linux kernel did not properly verify the directory contents permissions from within a unprivileged user namespace. A local attacker could use this to expose sensitive information (protected file names). (CVE-2018-6559) Update instructions: The problem can be corrected by updating your system to the following package versions: Ubuntu 18.10: linux-image-4.18.0-1006-aws 4.18.0-1006.7 linux-image-aws 4.18.0.1006.6 After a standard system update you need to reboot your computer to make all the necessary changes. XXX MAYBE WITH XXX 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://usn.ubuntu.com/usn/usn-3832-1 CVE-2018-17972, CVE-2018-18281, CVE-2018-18445, CVE-2018-18653, CVE-2018-18955, CVE-2018-6559 Package Information: https://launchpad.net/ubuntu/+source/linux-aws/4.18.0-1006.7 - -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEEpgY7tWAjCaQ8jrvULwmejQBegfQFAlwA3eIACgkQLwmejQBe gfQNlQ//eU4B/iW/E+h/KZ6tYFFnBQT41JUeBK3hxKKbel+gvoyDa8LclMf+xp6m n3moDrsB6CMO2t3rzkg6IRCrJwNqk+lSF8eiZoyNjJdTebDB34KK1CgVNTCKUKlx s04BcK28J3TwI7VSHsfBlAPaetN6lDJi9IlXzj3ovGJp1rBNPJGvuL+wJW2zlA7V 4c0TV0tki2tJVlcB4IDsHCSyNsiOD+PyuHYXEtSKf2cd5J+xrqg7a6CYsVbVYMeV aAcl5gVQ7iJMGRO2kB+FoK2uYK1njOdszS2esdBCrh4EXQQnj+RWC97WYQ6gux5O dUOG+miybLnFwvGbecaI98XS+JmhzEjlfmPYVht0Fu1Bc4tENyRgg/OSa74WD6WO dzd6fxAMe4GIOstKD0XhXgX8M1PXz4zF17wTJ+mScQDIv2tRs3D+NM34PGChjNXD Oe0aoil6x3qSfFd0Kw3r32CJZcqjbM4JH3mbbdsnwvzDhQ4I2qLACIeZdxdcnGvD yTXeh6+nNgEdkxt56RXxk7VwiUtPguWxwF8BrfzwT1oL3LurjMvmtLxZrwtOWslx f8PFTjjgunoO+xioibIjfCGkw00k0a85f4k97jsDsfuCSCsiW22ILwnClbdpItIZ x90A9p84QIQ7beohnFfcapVgX37Shc3vdcfJ08BTJ13JXPBcg+o= =JIcs - -----END PGP SIGNATURE----- - -------------------------------------------------------------------------------- ========================================================================== Ubuntu Security Notice USN-3833-1 November 30, 2018 linux-aws vulnerabilities ========================================================================== A security issue affects these releases of Ubuntu and its derivatives: - - Ubuntu 18.04 LTS Summary: Several security issues were fixed in the Linux kernel. Software Description: - - linux-aws: Linux kernel for Amazon Web Services (AWS) systems Details: Jann Horn discovered that the Linux kernel mishandles mapping UID or GID ranges inside nested user namespaces in some situations. A local attacker could use this to bypass access controls on resources outside the namespace. (CVE-2018-18955) Philipp Wendler discovered that the overlayfs implementation in the Linux kernel did not properly verify the directory contents permissions from within a unprivileged user namespace. A local attacker could use this to expose sensitive information (protected file names). (CVE-2018-6559) Update instructions: The problem can be corrected by updating your system to the following package versions: Ubuntu 18.04 LTS: linux-image-4.15.0-1029-aws 4.15.0-1029.30 linux-image-aws 4.15.0.1029.29 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://usn.ubuntu.com/usn/usn-3833-1 CVE-2018-18955, CVE-2018-6559 Package Information: https://launchpad.net/ubuntu/+source/linux-aws/4.15.0-1029.30 - --------------------------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 iQIVAwUBXAR8xmaOgq3Tt24GAQhREg/8D8l1iWWhA2j/b/OfQZ5Q/pJEWWVnNRY5 tXiWc/okWA9NnCf1JM4oF2nniy9nz3xKo9bUkv2Po70wbHLpKng3TBrpKLOVwZ8o oc5tmIByp1cpZpoJM2klH4ZIlz74/GjnoCIEqztT9BnjxvYBg0RONdi9vXgxpmNI uF90f3y1mZhnftvYje4udthQ0QFi5WUz5GSHJsxyHuAxreujinrf5B2sYkPJ3pOm y+dFn1nKfRmPhzBEukXnR1E0CJYRKn1GFwyTylJdO4rEyOmOdoCDcrIZnZ5O9vBh 3M9f5H3whVmCyqVcfq53rqUgod+nMlqBE/m8q2BIu/+lxSmuqUsI+EkkleP+H2Be ah0066ZMEbNZGHlpCWRrL9Xr6mku/T5ytU5zuKITATx8MY3RPy4lQ9lMpaG4V+dT RnPPNAP2IxFOlx8y/zYaPAW0k/Un84Cdxj6FZwEQj81k7CiakXIChFEEgfdMTZ9g f8yhNkahQPvTKPsPYmhoZnE0JU2VaeWexTAe9ATvi96GJKjd213jD2J9Yp1lsCAp pVM7kIHSZAVxH4rthDnOnsH/UXCOdo35B3p7W0lSjHUWNrqZvdvT+trpgYOrZT+R EHPQM75y+P6I0BjuYe6tVt9jXHvlFKlw0ZymfRWVWolxh+zt0HdS9I7cado2f2gh ZHWiu73Nonc= =rfWr -----END PGP SIGNATURE-----