Puppet before 2.6.17 and 2.7.x before 2.7.18, and Puppet Enterprise before 2.5.2, allows remote authenticated users to read arbitrary files on the puppet master server by leveraging an arbitrary user's certificate and private key in a GET request.
https://bugzilla.redhat.com/show_bug.cgi?id=839130
http://www.ubuntu.com/usn/USN-1506-1
http://www.debian.org/security/2012/dsa-2511
http://secunia.com/advisories/50014
http://puppetlabs.com/security/cve/cve-2012-3864/
http://lists.opensuse.org/opensuse-updates/2012-07/msg00036.html
http://lists.opensuse.org/opensuse-security-announce/2012-08/msg00006.html