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.
https://www.exploit-db.com/exploits/40937/
https://github.com/DonnchaC/ubuntu-apport-exploitation
https://bugs.launchpad.net/apport/+bug/1648806