Buffer overflow in the base64 decoder in MERCUR Mailserver 4.2 before SP3a allows remote attackers to cause a denial of service and possibly execute arbitrary code via a long (1) AUTH command to the POP3 server or (2) AUTHENTICATE command to the IMAP server.
Buffer overflow in the MERCUR WebView WebMail server allows remote attackers to cause a denial of service via a long mail_user parameter in the GET request.