The ACL plugin in Dovecot before 1.1.4 allows attackers to bypass intended access restrictions by using the "k" right to create unauthorized "parent/child/child" mailboxes.

The ACL plugin in Dovecot before 1.1.4 treats negative access rights as if they are positive access rights, which allows attackers to bypass intended access restrictions.

Argument injection vulnerability in Dovecot 1.0.x before 1.0.13, and 1.1.x before 1.1.rc3, when using blocking passdbs, allows remote attackers to bypass the password check via a password containing TAB characters, which are treated as argument delimiters that enable the skip_password_check field to be specified.

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.

Dovecot before 1.0.10, with certain configuration options including use of %variables, does not properly maintain the LDAP+auth cache, which might allow remote authenticated users to login as a different user who has the same password.