CVE 2012-1988
Puppet 2.6.x before 2.6.15 and 2.7.x before 2.7.13, and Puppet Enterprise (PE) Users 1.0, 1.1, 1.2.x, 2.0.x, and 2.5.x before 2.5.1 allows remote authenticated users with agent SSL keys and file-creation permissions on the puppet master to execute arbitrary commands by creating a file whose full pathname contains shell metacharacters, then performing a filebucket request.
See the
CVE page on Mitre.org
for more details.