A feature in LXD (LP#1829071), affects the default configuration of Ubuntu Server which allows privileged users in the lxd group to escalate their privilege to root without requiring a sudo password.

In the cron package through 3.0pl1-128 on Debian, and through 3.0pl1-128ubuntu2 on Ubuntu, the postinst maintainer script allows for group-crontab-to-root privilege escalation via symlink attacks against unsafe usage of the chown and chmod programs.

An issue was discovered in Apport before 2.20.4. There is a path traversal issue in the Apport crash file "Package" and "SourcePackage" fields. These fields are used to build a path to the package specific hook files in the /usr/share/apport/package-hooks/ directory. An attacker can exploit this path traversal to execute arbitrary Python files from the local system.

An issue was discovered in Apport before 2.20.4. In apport/ui.py, Apport reads the CrashDB field and it then evaluates the field as Python code if it begins with a "{". This allows remote attackers to execute arbitrary Python code.

The overlayfs implementation in the linux (aka Linux kernel) package before 3.19.0-21.21 in Ubuntu through 15.04 does not properly check permissions for file creation in the upper filesystem directory, which allows local users to obtain root access by leveraging a configuration in which overlayfs is permitted in an arbitrary mount namespace.