The ACL plugin in Dovecot 1.2.x before 1.2.13 propagates INBOX ACLs to newly created mailboxes in certain configurations, which might allow remote attackers to read mailboxes that have unintended weak ACLs.
lists.opensuse.org/opensuse-security-announce/2010-09/msg00006.html
secunia.com/advisories/43220
www.dovecot.org/list/dovecot-news/2010-July/000163.html
www.mandriva.com/security/advisories?name=MDVSA-2010:217
www.openwall.com/lists/oss-security/2010/09/16/14
www.openwall.com/lists/oss-security/2010/09/16/17
www.securityfocus.com/bid/41964
www.ubuntu.com/usn/USN-1059-1
www.vupen.com/english/advisories/2010/2840
www.vupen.com/english/advisories/2011/0301