dovecot is vulnerable to authorization bypass attacks. The vulnerability exists as script-login in Dovecot 2.0.x before 2.0.13 does not follow the user and group configuration settings, which might allow remote authenticated users to bypass intended access restrictions by leveraging a script.
dovecot.org/pipermail/dovecot/2011-May/059085.html
openwall.com/lists/oss-security/2011/05/18/4
rhn.redhat.com/errata/RHSA-2013-0520.html
secunia.com/advisories/52311
www.dovecot.org/doc/NEWS-2.0
www.securityfocus.com/bid/48003
access.redhat.com/security/updates/classification/#low
exchange.xforce.ibmcloud.com/vulnerabilities/67675
rhn.redhat.com/errata/RHSA-2013-0520.html