========================================================================= 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