How to protect your ISPConfig 3 Server against the Logjam attack
This post is from 2015. Versions, commands and links in it may be outdated. The current release is ISPConfig 3.3.2p1.
This tutorial describes the steps that need to be taken to protect your Ubuntu or Debian Linux Server against the recently detected Logjam attack. Logjam is an attack against the Diffie-Hellman key exchange which is used in popular encryption protocols like HTTPS, TLS, SMTPS, SSH and others.
This tutorial is compatible with ISPConfig 3 setups on Debian and Ubuntu.