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

—–BEGIN PGP SIGNATURE—–
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=tF5P
—–END PGP SIGNATURE—–
—