Dovecot before 1.0.11, when configured to use mail_extra_groups to allow Dovecot to create dotlocks in /var/mail, might allow local users to read sensitive mail files for other users, or modify files or directories that are writable by group, via a symlink attack.
https://www.redhat.com/archives/fedora-package-announce/2008-March/msg00381.html
https://www.redhat.com/archives/fedora-package-announce/2008-March/msg00358.html
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A10739
https://exchange.xforce.ibmcloud.com/vulnerabilities/41009
http://www.securityfocus.com/bid/28092
http://www.securityfocus.com/archive/1/489133/100/0/threaded
http://www.redhat.com/support/errata/RHSA-2008-0297.html
http://www.dovecot.org/list/dovecot-news/2008-March/000061.html
http://www.debian.org/security/2008/dsa-1516
http://security.gentoo.org/glsa/glsa-200803-25.xml
http://secunia.com/advisories/32151
http://secunia.com/advisories/30342
http://secunia.com/advisories/29557
http://secunia.com/advisories/29396
http://secunia.com/advisories/29385
http://secunia.com/advisories/29226
http://lists.opensuse.org/opensuse-security-announce/2008-10/msg00004.html