An information leak vulnerability in rfc822_parse_domain was found in dovecot, affecting versions 2.0 - 2.2.33 and 2.3.0.
A malicious party can send a specially crafted email to a vulnerable system, causing it to crash dovecot. In some systems, the mail can be stored into the mail system, causing crash every time it is being opened. If the mail is stored into the mail system, it can be used to also leak heap memory from IMAP process by requesting bodystructure of the mail.