=========================================================================Ubuntu Security Notice USN-3748-1
August 21, 2018

base-files vulnerability
=========================================================================
A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 18.04 LTS

Summary:

base-files could be made to hang or overwrite files as the administrator.

Software Description:
- base-files: Debian base system miscellaneous files

Details:

Sander Bos discovered that the MOTD update script incorrectly handled
temporary files. A local attacker could use this issue to cause a denial of
service, or possibly escalate privileges if kernel symlink restrictions
were disabled.

Update instructions:

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 18.04 LTS:
  base-files                      10.1ubuntu2.2

In general, a standard system update will make all the necessary changes.

References:
  https://ubuntu.com/security/notices/USN-3748-1
  CVE-2018-6557

Package Information:
  https://launchpad.net/ubuntu/+source/base-files/10.1ubuntu2.2