Fetchmail is vulnerable to informaiton disclosure. It fails to enforce STARTTLS session encryption in some circumstances, such as a certain situation with IMAP and PREAUTH.
www.openwall.com/lists/oss-security/2021/08/27/3
lists.fedoraproject.org/archives/list/[email protected]/message/L3XJ6XLEJCEZCAM5LGGD6XBCC522QLG4/
lists.fedoraproject.org/archives/list/[email protected]/message/VXMKSEHAQSEDCWZMAOJEGX3P3JW6QY6H/
lists.fedoraproject.org/archives/list/[email protected]/message/ZYCYLL73NP7ALJWSDICIVSA47ZIXWSSA/
nostarttls.secvuln.info/
secdb.alpinelinux.org/edge/community.yaml
secdb.alpinelinux.org/v3.14/community.yaml
www.fetchmail.info/security.html