Puppet 2.6.x before 2.6.12 and 2.7.x before 2.7.6, and Puppet Enterprise (PE) Users 1.0, 1.1, and 1.2 before 1.2.4, when signing an agent certificate, adds the Puppet master's certdnsnames values to the X.509 Subject Alternative Name field of the certificate, which allows remote attackers to spoof a Puppet master via a man-in-the-middle (MITM) attack against an agent that uses an alternate DNS name for the master, aka "AltNames Vulnerability."
Puppet 2.6.x before 2.6.14 and 2.7.x before 2.7.11, and Puppet Enterprise (PE) Users 1.0, 1.1, 1.2.x, 2.0.x before 2.0.3, when managing a user login file with the k5login resource type, allows local users to gain privileges via a symlink attack on .k5login.
The changeuser method in the SUIDManager (lib/puppet/util/suidmanager.rb) in Puppet 2.6.x before 2.6.14 and 2.7.x before 2.7.11, and Puppet Enterprise (PE) Users 1.0, 1.1, 1.2.x, 2.0.x before 2.0.3 does not properly manage group privileges, which allows local users to gain privileges via vectors related to (1) the changeuser not dropping supplementary groups in certain conditions, (2) changes to the eguid without associated changes to the egid, or (3) the addition of the real gid to supplementary groups.