Alpine Project Alpine any version

Alpine before 2.23 silently proceeds to use an insecure connection after a /tls is sent in certain circumstances involving PREAUTH, which is a less secure behavior than the alternative of closing the connection and letting the user decide what they would like to do.

URL access filters bypass in Alpine

Authentication bypass in Alpine

In Alpine before 2.25, untagged responses from an IMAP server are accepted before STARTTLS.

Alpine before 2.25 allows remote attackers to cause a denial of service (application crash) when LIST or LSUB is sent before STARTTLS.