Puppet 2.7.x before 2.7.21 and 3.1.x before 3.1.1, when running Ruby 1.9.3 or later, allows remote attackers to execute arbitrary code via vectors related to "serialized attributes."
https://puppetlabs.com/security/cve/cve-2013-1655/
http://www.securityfocus.com/bid/58442
http://www.debian.org/security/2013/dsa-2643
http://ubuntu.com/usn/usn-1759-1
http://secunia.com/advisories/52596
http://lists.opensuse.org/opensuse-updates/2013-04/msg00056.html
http://lists.opensuse.org/opensuse-security-announce/2013-04/msg00004.html