[SECURITY] [DLA 186-1] mailman security update

Package : mailman
Version : 1:2.1.13-6
CVE ID : CVE-2015-2775
Debian Bug : 781626

A path traversal vulnerability was discovered in Mailman, the mailing
list manager. Installations using a transport script (such as
postfix-to-mailman.py) to interface with their MTA instead of static
aliases were vulnerable to a path traversal attack. To successfully
exploit this, an attacker needs write access on the local file system.