The change_user 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 change_user 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.
lists.opensuse.org/opensuse-security-announce/2012-03/msg00003.html
projects.puppetlabs.com/issues/12457
projects.puppetlabs.com/issues/12458
projects.puppetlabs.com/issues/12459
projects.puppetlabs.com/projects/1/wiki/Release_Notes#2.6.14
puppetlabs.com/security/cve/cve-2012-1053/
secunia.com/advisories/48157
secunia.com/advisories/48161
secunia.com/advisories/48166
secunia.com/advisories/48290
ubuntu.com/usn/usn-1372-1
www.debian.org/security/2012/dsa-2419
www.osvdb.org/79495
www.securityfocus.com/bid/52158
exchange.xforce.ibmcloud.com/vulnerabilities/73445
hermes.opensuse.org/messages/15087408