Vulnerabilities

An attacker can cause uncontrolled memory usage with excessive bracing over IMAP.

Attacker can use the IMAP SETACL command to inject the anyone permission to user's dovecot-acl file even if imap_acl_allow_anyone=no.

Attacker can upload a malicious Sieve script over ManageSieve service (or locally) to bypass configured CPU time limits for Sieve up to 130 times of the configured limit.

Attacker can use a specially crafted base64 exchange between Dovecot and Client to fake SCRAM TLS channel binding.

When safe filter is used with variable expansion, all following pipelines on the same string are incorrectly interpreted as safe too, enabling unsafe data to be unescaped.

If auth_username_chars is empty, it is possible to inject arbitrary LDAP filter to Dovecot's LDAP authentication.

A mail message containing excessive amount of RFC 2231 MIME parameters causes LMTP to use too much CPU.

Attacker can send a specifically crafted message before authentication that causes managesieve to allocate large amount of memory.

Sending "NOOP (((...)))" command with 4000 parenthesis open+close results in ~1MB extra memory usage.

Doveadm credentials are verified using direct comparison which is susceptible to timing oracle attack.

Dovecot OTP authentication is vulnerable to replay attack under specific conditions.

Dovecot SQL based authentication can be bypassed when auth_username_chars is cleared by admin.

When dovecot has been configured to use per-domain passwd files, and they are placed one path component above /etc, or slash has been added to allowed characters, path traversal can happen if the domain component is dire…

ManageSieve AUTHENTICATE command crashes when using literal as SASL initial response.

Dovecot has provided a script to use for attachment to text conversion.

When sending invalid base64 SASL data, login process is disconnected from the auth server, causing all active authentication sessions to fail.

An issue was discovered in the auth component in Dovecot 2.2 and 2.3 before 2.3.20.

The Sieve engine in Dovecot before 2.3.15 allows Uncontrolled Resource Consumption, as demonstrated by a situation with a complex regular expression for the regex extension.

The submission service in Dovecot before 2.3.15 allows STARTTLS command injection in lib-smtp.

Dovecot before 2.3.15 allows ../ Path Traversal.

An issue was discovered in Dovecot before 2.3.13.

Dovecot before 2.3.13 has Improper Input Validation in lda, lmtp, and imap, leading to an application crash via a crafted email message with certain choices for ten thousand MIME parts.

In Dovecot before 2.3.11.3, sending a specially formatted RPA request will crash the auth service because a length of zero is mishandled.

In Dovecot before 2.3.11.3, sending a specially formatted NTLM request will crash the auth service because of an out-of-bounds read.

In Dovecot before 2.3.11.3, uncontrolled recursion in submission, lmtp, and lda allows remote attackers to cause a denial of service (resource consumption) via a crafted e-mail message with deeply nested MIME parts.