MailScanner before 4.0 5-1 and before 3.2 6-1 allows remote attackers to bypass protection via attachments with a filename with (1) extra l…

MailScanner before 4.0 5-1 and before 3.2 6-1 allows remote attackers to bypass protection via attachments with a filename with (1) extra leading spaces, (2) extra trailing spaces, or (3) alternate character encodings that cannot be processed by MailScanner.